There's a really big one just down the road from here - it's uncovered, open all year round, and large enough to accommodate lots and lots of people, all at the same time.

One occasionally has to watch out for the ferries, paddle steamers and other vessels that go up and down and across it, but apart from that it's very nice - and best of all, it's free!

PM me, and I'll send you the address. I wouldn't want to give the secret away to every Urs, Dick and Harry on the forum...