Having a connected flight through Amsterdam to Paris, we decided to visit Amsterdam for 2 hours. It was morning so we didn't manage to see the vicious windows of the Red Light District there, but we walked down the streets, saw the canals (looking like a cobweb on the city map), breweries, diamond museums, coffee shops, cannabis smoking tool shops (even penis-shaped), sex shops with condoms hanging in the windows and so on. Everything is legal, nothing is forbidden.