
Tate Modern used to have a perfectly good bike shed to park in, which everyone ignored because the railings outside the entrance were more convenient.
Now, the bike shed has disappeared as part of the development works to the south of the main building. So the railings are now the only place you can park your bike anyway, legitimised by a sign.
Which is fine, but slapped wrists to Tate for removing the bike section from their how-to-get-here web page. They used to be cited by the LCC (still are, actually) as a good example of an attraction whose website encourages you to cycle there.
Not any longer. There's info on getting there by boat, tube, bus, taxi, car, coach, camel - OK, I was lying about the camel. But nothing about bikes, not even hire bikes. (There are three fairly convenient docking stations, which surely ought to be pointed out on their website. What do they think those lines of identical bikes are? An installation?)
Talking of which, Marcel Duchamp was a keen cyclist, of course, as we know from his Bicycle Wheel of 1913. It was originally going to be an entire bike, but he left it fastened by only one D-lock to a rack in Waterloo.
Update: The Tate Modern website has now been updated (though only with info about hire bikes). Maybe they've been reading this blog.

So, in the spirit of reinvention, we've chosen
Tate Modern has temporary paid-for exhibitions, but most of it is free. Big stuff (usually the headline temporary exhibit) goes in the massive Turbine Hall, and often seems only loosely describable as 'art': at certain 'exhibitions' we've spent happy hours sliding down flumes and exploring circus-style adventure playgrounds and didn't know we were being all clever and artistic.
And Tate Modern is an excellent place to visit by bike, right on the riverside path that you can cycle (pretty much all the way) from Vauxhall to Tower Bridge. It seems OK to park on the railings right outside the entrance now (right, more convenient than the covered bike shed next to it): for a while earlier this year they
You can wander round the galleries and talk bollocks about the exhibits confidently in a loud voice, having ensured first that what you're commenting on really is a work of art and not a lift or cleaner's cupboard or something. 
And then you can go up to the bar on Floor 7 for one of London's best evening barstool views: a half-panoramic sweep of the Thames with St Paul's, the Wobbly Bridge etc. You can always grab a spot by the window, the wine's not too expensive, and you can watch the townscape watercolours change as the sun sags low and pink.
The inverted camera-obscura view through a wine glass is particularly enjoyable. And your transport home is right outside. We like biking round London.

And Tate Modern's bike parking landscape has changed. Signs have been cable-tied to the railings saying 'Bicycles left attached to these railings will be removed. Please use bicycle racks provided.' 

We're not being contrary or ungrateful. It simply goes to show that we expect cycling to be a door-to-door activity. That's the beauty of it.