When the big, crescented County Hall was christened in 1922 by a king with a big hat, everything about it said this was big news. This was a big new building with a big new purpose — housing London County Council, a big new setup with big new responsibilities. In 1965 things got bigger, when the Greater London Council (GLC) moved in — their job, to preside over a London that had just got a lot bigger.
Then, in 1986, the prime minister closed it all down.
The most poignant reminder of County Hall's former occupants is the old library, still stocked with the GLC's tomes — titles like The International Who's Who 1958 — as if they still intend to pop back for them sometime. You can take afternoon tea among the books and busts but it's unlikely you'll bump into Ken Livingstone now.
The original purpose of County Hall may have been dissolved but its vastness remains. Aside from the posh Marriott Hotel they've tried to fill the place up with Merlin hijinks; an ersatz dungeon and a few sharks, but it seems the Japanese owner is reluctant to have too many tenants, and swathes of the baroque palace remains empty. Incredible really, in what is the juiciest of prime London real estate.
Some space, though, is used to great effect; no more so than on the sixth floor of the Marriott, where they've got the largest hotel pool in London.
From pools with reclining roofs to pools that look like nightclubs, London's hotel scene has everything — everything, that is, apart from length. No matter how luxurious some of these experiences are, you sometimes can't help feeling you're posh sardines in a chlorine brine.
Not so with the Marriott's 25 metre long dip — given the feel of a watery boulevard thanks to the eight spindly palms that flank it. Arboreal decor aside it's not all that deep (1.4 metres end to end), and it's on the slim side. So what's the difference between this 25 metres and the 25 metres at your local leisure centre?
Well, this one's got all the perks of a private club (sauna, steam room, sprawling gym, loungers, daily newspapers) but in this case — and not sure we mentioned this — the pool is 25 metres long. It is pretty much the only 'luxury' swim in London where you can properly swim.
One other thing: whenever you need a breather, you can step out on onto a balcony positioned just above the fat County Hall sign and check up on Parliament across the Thames. Fingers crossed no one over there is cooking up a scheme to abolish this pool.
Monthly club and spa membership starts from £100 (corporate £69).