The Nileometer was built to measure the height of the Nile floods and is on the tip of one of the central islands I think. It's a lovely piece of Islamic architecture but to get the best out of it you should walk down the steps (watch out - there's no rails) to the bottom of the well. The view of the ceiling is amazing - well worth it.
Send your feedback or queries to been.there@guardian.co.uk
Search Been there