Well I've just got back from a nice night out on a company do at Spitbank Fort just off the south coast in Portsmouth. It's an old defence fort dating back to the 1800s.
Short ferry ride across (a little choppy!) and we were there. Facinating building, lots of history good food, friendly staff (both ours and theirs). Unusually for a works do, everyone seemed to be well behaved and I didn't see anyone getting too drunk even though there was a free bar. I even did a little dancing (even if it was like you cliche'd wedding disco).
Managed to bang my forehead on a cast-iron hook sticking out from one of the walls which came up in a nice lump. There's also a 400ft passageway around the perimiter of the fort that is pitch black and is quite creepy when using candles.