When my family and I went to Aberystwyth in Wales last month, we visited the Ceredigion County Museum and saw an amusing exhibition called At Your Convenience all about historic toilets. The hardworking curators had amassed an impressive collection privies, commodes, chamber pots, early flush toilets, even an entire outhouse.

Needless to say, my five-year-old son loved this. Imagine, getting to make toilet jokes under the guise of education! This chair that lifts up to reveal a chamber pot especially impressed him until he noticed the yellow stains.

Being the highbrow kind of guy I am, I'm always interested to see historic toilets. These don't get mentioned in history books much, and are generally not displayed in museums, which makes this exhibition a pleasant surprise. That such an important day-to-day item is blotted out of history tells us something about how the past is written and presented.

The sharp-eyed traveler can still discover privies from the past. Many survive in Roman archaeological sites. Ephesus has well-preserved Roman latrinae consisting of a stone benches with holes in them. Housesteads Roman Fort along the Hadrian's Wall Path has a military toilet that gets lots of attention from younger visitors. The Romans had running water to clean these commodes.

They weren't the first, however. The Neolithic settlement of Skara Brae in the Orkney Islands had flush toilets 5,000 years ago. The ancient city of Mohenjo-Daro in Pakistan had toilets at around the same time. More modern toilets can be of interest too. In Addis Ababa, the Institute of Ethiopian Studies is housed in one of Haile Selassie's palaces. The tour takes you through his private chambers, where you can visit the Imperial bathroom and see his baby blue toilet and bidet. Sadly, they don't let you take photos.

Loo lovers will want to check out the Museum Für Historische Sanitärobjeckte in Gmunden, Austria. This toilet museum has probably the largest collection in the world. There's a great gallery of photos here.

At Your Convenience is open until September 3.

Gallery: Toilets of yesteryear