Just had a thought about a swim really close to home. It's not as romantic as any of the locations that you've all done but it's a big mass of water and it's outdoors: Greenland Dock, Surrey Quays
Thoughts?
(I've actually swan there before many years ago.)
You can but these days the Council seem to control what goes on there and it's part of the 'Surrey Docks Watersports Centre'. According to the website, they offer sailing, windsurfing, kayaking, powerboating and raft building in the dock but it aint free...http://www.fusion-lifestyle.com/centres/Surrey_Docks_Watersports_Centre