A toilet at Dover Castle, UK, located in secret tunnels inside the white cliffs of Dover, is featured in Luke Barclay's book A Loo with a View. The toilet has a brilliant view of Dover Harbour through a window in the cliff and in 1940 would have offered a view of the famous WWII Dunkirk Evacuations. It is possible to see this toilet on the tour of the tunnels.
Check out the Pump Aid website to learn about the fantastic work this charity does in breaking the 'toilet taboo' and improving sanitation facilities, particularly in Africa.
Check out the Toilet Twinning charity website. You can twin your toilet with toilets around the world, which is clearly amazing.
Croquet - nothing to do with loos but a great game nonetheless.
The Copeland Island Bird Observatory in Northern Ireland has a toilet featured in the A Loo with a View books.
The World Toilet Organization OR WTO for short. Not to be confused with the World Trade Organisation, of course...