The UK's longest-running holiday operator Thomas Cook is offering family tours of Amsterdam's red-light district. The package costs £12, though half-price for children. Thomas Cook claims the tour, which is free to under threes, offers a 'fascinating insight into the oldest profession in the world'. A press release on the two-hour tour says it leaves at 8pm and 'will take visitors deep into the famous red-light district, accompanied by a reliable and trustworthy guide'. The brochure says: 'Begin with a drink at a prostitute information centre where a former prostitute will explain the system and answer any questions you may have. Then head for the Wallen (the red-light district) and see for yourself.'