"The Romans had pretty sophisticated toilets, often with running water and stone seats. But up in the north end of Roman Britain, where they were building Hadrian's Wall, a stone seat would be pretty uncomfortable. Now archaeologists working at Vindolanda, a Roman fort near the wall, have dug up a well-preserved, albeit well-used wooden toilet seat in what appears to be the fort's dump. Director of Excavations, Dr Andrew Birleysays in a press release:"
http://www.treehugger.com/bathroom-design/worlds-oldest-wooden-toilet-seat-discovered-hadrians-wall.html