Modern places usually have UK-style sockets.

In older budget places you often get European 2-pin style sockets and 3 round pin ones that I haven't seen anywhere else. If you don't have an adaptor for the latter type, European-style 2-pin plugs and adaptors can be usually be made to fit at a push. Pushing a match or similar into the "earth" hole releases the live and neutral holes, allowing a European style 2-pin plug or adaptor to be inserted. Although the pins on a European plug are too close together to go all the way in, they normally go far enough in to get a connection. Not that I'm suggesting that you do it, of course. I wouldn't want the men in powder-grey suits from Ambulance Chasers 4 U coming after me if something goes wrong!