The Flask is a Young's pub in Hampstead, which takes a pride in its cask ales. There are quiz nights, and live Jazz sessions on some nights of the week, and it's a great place to come and hang out and have a quiet chat with your friends when the music's not on too. Back in the eighteenth century, a pub on this site used to sell fresh water to the rest of London, collected from local springs, which probably gave the pub its current name. Today, the beer might not have as many medicinal qualities as that water was reputed to have, but a night spent here will warm the cockles of your heart nonetheless.