After Rome was destroyed by the Visigoths in 410, Emperor Constantine the Great chose a small fishing village on the Bosphorus to become the new imperial capital. This small fishing village was inaugurated as Constantinople, what we now know as Istanbul. The Roman empire based in Constantinople is usually referred to as the Byzantine Empire.

There are many artefacts relating to the Byzantine Empire in Istanbul, but the Beetle's favourite is the Byzantine cisterns. If you've seen the James Bond movie, From Russia with Love, maybe you remember the scene where the redoubtable Mr Bond is rowing in a small boat through a forest of marble columns – this was filmed in Yerebatan Saray Sarniçi.

This cistern is thought to have been built in 532 AD, using marble columns recycled from Greek ruins in and around the Bosphorus. The water was routed from reservoirs around the Black Sea and transported via the Aqueduct of Valens. It was used as a backup for periods of drought or siege for the Great Palace. Historians believe that the cisterns were left largely untouched by the Ottomans, who preferred running, not stagnant, water, and the stored water ended up being used to water the Topkapi Gardens. The cistern was later left to collect silt and mud until it was cleaned by the Istanbul Municipality and opened to the public in 1987.

It is just one of many cisterns underneath modern day Istanbul, and the largest at 70 x 140 metres, (or 2.4 acres), and can hold 80,000 cubic metres – over 21 million US gallons). It is very grand and there are twelve rows of 28 columns each making an impressive total of 336 marble columns and you walk between the columns on a large boardwalk. At the far end of the walkway are two large Medusa heads in the north-western corner, one inverted and the other on its side; according to mythology, placing her this way caused her to turn herself into stone. Another theory is that turning her upside down neutralises her powers. There are some huge fish too in the water whose function is to aerate the water (and feed on tourists' handouts). There are signs giving details of classical concerts that take place in the cisterns. The Basilica Cistern was restored in 1980 for visitors.

There's also a café with wobbly metal tables and chairs and orange lighting adding to the subterranean feeling.

Yerebatan is in Sultanahmet Square, at the north-eastern end of the Hippodrome, just off Divan Yolu, and across the street from Ayasofya (Hagia Sophia). Opening hours: Daily 0900-1700. Admission: $3.50.

As a result of last month's feature on the world's smallest countries, David wrote in to say:

Ahh, but what about the Sovereign Military Hospitable Order of St. John of Jerusalem, Rhodes, and Malta, which has diplomatic ties with 87 countries, its own license plates, postage stamps passports, and currency, and runs dozens of hospitals and clinics worldwide. Its sovereign territory is a second floor office suite in the Palazzo Malta at 68 via de Candiotti in Rome, and an applicant for UN membership.

Slightly larger, but not as big as Vatican City, we of course have Sealand, which you probably know–six miles off the English coast, a WWII antiaircraft tower “liberated” in 1967 by Major and Mrs. Roy Bates.

What do you think? Let the Beetle know!

For a truly unique experience with nature, you can't beat Xcarat in the Cancun area of Mexico.

Best known for the swimming with dolphins opportunity they offer, most tourists flock there for the experience, and it is well worth it. For a reasonable fee you have about an hour with the dolphins. The trainers teach you about their habits in the wild and how they interact with humans. At some point you are allowed to pet them and feel connected with these incredible animals. The trainers then get the dolphins to do tricks in the pool and even jump over you in incredible formation. It is all caught on video tape and photos that you can purchase after the experience. It was incredible to me, after viewing the video tape, to see how close the dolphins came to us before leaping up behind us and jumping over our heads. When you are in the pool waiting for them to jump you actually don't feel them behind you. You just suddenly see them over you. That proved to me how graceful they are in the water and how they could be inches away from you without you even realizing it. It was a truly thrilling experience.

The rest of the park is also amazing. We saw an exhibit with quails, hatching before your eyes, out of their eggs. It is a credit to the park that before you enter, they supply you with sunscreen made from only natural ingredients. So you don't harm the animals with which you interact.

Also available is a wonderful open exhibit with local birds, monkeys and even baby crocodiles. You walk along a paved walkway and all the creatures are out in the open, so it's almost like being in the forest itself, with nothing between you and the animals. The variety of birds is spectacular and the colours are a real feast for the eyes. Just when you think you know what to expect something surprises and delights you. For example, at one point we were only expecting to see more birds but were pleasantly surprised to look up and saw a large family of monkeys, directly above us. The male of the group became territorial and to protect his family threw branches at us. It was truly an interactive experience and something we weren't expecting.

There are also guides around that allow you to hold a small crocodile; still another photo op! You can even walk up to some of the larger parrots to pet them. Don't try this while they are eating though, because they think you are trying to steal their food. But it was really incredible seeing all this wildlife and actually being able to touch and interact with them.

Xcarat is truly a must see for nature lovers as well as those who want to experience local animal and bird life.

The Human Development Index (HDI), published annually by the UN, ranks nations according to their citizens' quality of life rather than strictly by a nation's traditional economic figures. The criteria for calculating rankings include life expectancy, educational attainment, and adjusted real income.

Source: www.infoplease.com

What is it: hookworm is an intestinal parasite of humans that usually causes mild diarrhoea or cramps. Heavy infection with hookworm can create serious health problems for newborns, children, and pregnant women. Hookworm infections occur mostly in tropical and subtropical climates and are estimated to infect about 1 billion people — about one-fifth of the world's population. One of the most common species is found in southern Europe, northern Africa, northern Asia, and parts of South America. Hookworm eggs require warm, moist, shaded soil to hatch into larvae. The larvae are hardly visible and penetrate the skin (often through bare feet), and are carried to the lungs. Then they go through the respiratory tract to the mouth where they are swallowed, and eventually reach the small intestine. This journey takes about a week. In the small intestine, the larvae develop into half-inch-long worms, attaching themselves to the intestinal wall, where they suck blood. The adult worms produce thousands of eggs. These eggs are passed in human faeces (stools).

How do I get it: you can become infected by direct contact with contaminated soil, usually by walking barefoot, or accidentally swallowing contaminated soil. Children in the countries or areas above are most likely at risk because they often play in dirt and go barefoot. Since transmission of hookworm infection requires development of the larvae in soil, hookworm cannot be spread person to person.

What happens if I get it: itching and a rash at the site of where the skin touched soil or sand is usually the first sign of infection. These symptoms occur when the larvae penetrate the skin. While a light infection may show no symptoms, heavy infection can cause anaemia, abdominal pain, diarrhoea, loss of appetite, and weight loss. Heavy, chronic infections can cause stunted growth and mental development.

Diagnose and treatment: the infection is diagnosed by identifying hookworm eggs in a stool sample. Hookworm infections are generally treated for 1-3 days with medication prescribed by your health care provider.

How can I avoid contracting hookworm: don't not walk barefoot or have contact with the soil with bare hands in areas where hookworm is common or there is likely to be faeces in the soil or sand.

Sally, from Malmsbury, Wiltshire in the UK packed her bags a few years ago to make a new home for herself in a small village near Estoril, Lisbon in Portugal. She works as an English as a Foreign Language teacher and here are some of her latest exploits. If you have ever thought or dreamt about becoming a TEFL teacher, then this may provide some inspiration.

I had an interesting job just after Christmas. I was asked to go to Lisbon to assess the level of English of six candidates for a job with a large insurance company. As it was 9.00 in the morning I decided to take the train. So I got up early, got the bus and then the train into Lisbon. It brought back vivid memories of all those months I commuted from Chippenham to Richmond just outside London, except that stood on a chilly platform at Estoril gazing at a blue sea certainly beat standing on a freezing platform at Chippenham and gazing at a car park with bored seagulls. The crowds negotiating train to metro were just like dear old Paddington but hey, trains coincide with the metro and I was at my appointment at 8.50 – not bad eh?

I really enjoyed the interviewing. They all sat round the table and I kicked off a conversation asking them what they all did – some were very good and articulate but there was the usual “I am better than all the rest” one who got on peoples' nerves. I then asked them to write a letter of application in English applying for the job and giving reasons why they thought they were suitable. This narrowed the field tremendously as although they could speak English well, their written work let them down. I managed to shortlist three with one clear contender and then was very pleased when the HR lady told me I had picked the three she had thought were right for the second stage. Result!

Teaching is still fun – I now have an Argentinean plastic surgeon who wants to move to England and has limited English. Joaquim is 33 and has been in Portugal for three years. His brother is a GP in Patagonia. He wants to have his own clinic eventually back in Argentina but the timing is not right at the moment. He is very keen for people to visit the country as the currency exchange is in our favour and not theirs at the moment. I took him on a practical lesson the other Saturday – a tour of Jumbo supermarket and Cascais fruit and vegetable market – he really enjoyed it.

I have also got a new class at a huge toy store. They are a hoot. They are all in the office and I do two hours with them usually on a Tuesday night. It's nice when you work on site as you get to see them in situ. They are very friendly with a wicked sense of humour and don't want books, just conversation and how to deal with English phone calls. One of my students has a great catchphrase when she doesn't understand – “whattee”. They are very interesting and ask intelligent questions regarding translations of phrases or as last week, the headings on a financial spreadsheet. When the Head of HR is not in the lesson, the questions tend to get more relaxed as in “Miss Sally, tell us some swear words in English”! Body parts are also of great amusement.

Jeronimos Monastery, Lisbon, photo by the Beetle

Jorge, my Siemens student, is constantly keeping me amused – if it's not the latest scandal in football, it's the problems at work and the entertaining saga of getting building permits and planning permission for his new house. He is a real pleasure to teach because he is such fun. In fact the whole office makes me very welcome and they all come over and chat and tell me whether they think he is improving or not. He went to Dresden two weeks ago that meant a couple of German/Portuguese/English lessons – I seem to be learning bits of German as well as Spanish these days.

Last week I gave him a crash course in football reporting – three English articles on Jose Mourinho and Chelsea – very amusing and of great interest to the other guys in the office that wanted to know what he was reading. I was very pleased when he told me that he had tried to read English articles on the plane to Dresden.

Tatiana, my tourism student, is having problems working on essays so we have been trying to break her block. We did a short one last week that was basically a précis of a Portuguese legend from Nazare. I'm hoping that the work we did will give her the confidence she needs. We started meeting in the coffee bar at Jumbo supermarket but the smoke was a pain on days when we couldn't sit outside, so then we moved to Cascais Library, where they have tables and chairs (and resident cat) outside but that got too cold. We then found a very nice pastelaria (Lua da Mel or Honeymoon) but recently she has had problems with babysitters, so we have the class in her flat with her baby daughter, Ayeesha who is very sweet and loves unloading my bag and pinching pencils.

Outdoor enthusiasts and holidaymakers planning trips to central and eastern Europe this year are being warned about a potentially life-threatening disease.

The 'Tick Alert' awareness campaign urges travellers to 16 named European countries, including many of the new popular destinations for outdoor tourism such as Croatia, Slovenia and Slovakia, to protect themselves against Tick Borne Encephalitis (TBE).

Increased tourism to rural and woodland areas of endemic countries in Europe is increasing the risk to visiting UK outdoor enthusiasts, the majority of whom remain unaware of the disease, how it is contracted or that they are members of a high-risk travel group.

TBE is a potentially life-threatening viral disease that can lead to meningitis and in serious cases can result in paralysis and death. It is transmitted via the bite of an infected tick, found typically in rural and forest areas up to a height of 3,000ft and occurs mainly during the late spring and summer months. The disease can also be transmitted by the ingestion of unpasteurised milk.

There has been a dramatic rise in the incidence of tick-borne diseases in central and eastern Europe over the last 10 years. TBE is now endemic in countries spreading from Sweden, across the Baltics and down to Croatia.

The fact that a number of endemic countries conduct intensive inoculation programmes for their resident populations should be heeded by all UK visitors.

“There is a low awareness of TBE, even among people experienced in outdoor activities abroad,” said Tick Alert's Lynda Bramham. “The aim of this campaign is to encourage anyone travelling to TBE endemic regions, and at risk of the disease through their outdoor leisure activity, to take effective precautions.”

Official figures show the number of UK tourists to the former Yugoslavia rose by 40 per cent last summer to 114,000 compared with the previous 12 months. Similarly, visitors to central and eastern Europe reached 558,000, an increase of 38 per cent.

Adventure travel, hiking and mountain biking in Europe are all increasing in popularity as people discover these new destinations.

A 2004 report by Mintel highlighted the growth of agritourism and countryside holidays in places such as Croatia and Estonia, and the Association of British Travel Agents (ABTA) lists Slovenia and Bulgaria among its hot tips for holidays in 2005.

Professor Sarah Randolph, head of the Oxford Tick Research Group at the University of Oxford said: “In some countries of mainland Europe the most serious vector-borne disease is caused by a virus transmitted by ticks, tick-borne encephalitis (TBE), which may kill one in every hundred people infected.”

There are a number of bite prevention measures that can be taken to reduce the risk of infection: these include using an insect repellent, wearing protective clothing to cover all areas of exposed skin, regularly inspecting your body for tick bites and carefully removing any that are found. However, the Foreign Office advises that travellers to TBE endemic regions seek inoculation advice form their local surgery of clinic – well before travelling.

Immunisation against TBE is available as a paid-for travel vaccine from specialist travel health clinics operated by MASTA, the UK's leading provider, and at GP surgeries and healthcare centres. For further information and advice for travellers visit www.masta.org/tickalert