London not only contains some of the best museums on the planet but the best free museums on the planet. To top it off, it also turns out to have the best free late opening museums on the planet. Super mega triple jackpot; London is the restless traveller's paradise. So far, after a lazy start, we've already popped into the houses of parliament, ambled around the Imperial War Museum and now we still have time left to inspect the Tate Modern, open until 10pm on Fridays and Saturdays.

Tate Modern houses one of the biggest and best collections of modern art in the world and had actually been top of my list of things to see in London. Aware that modern art is not to everyone's taste (although these people are clearly wrong) , discovering that it opened late was a blessing: should worst comes to worst and it's not a popular choice then at least we didn't come here at the expense of doing something else we'd both enjoy. All parties agree to give it a try. Sure it's free! What else would we be doing!

First exhibit is in the famous Turbine Hall; we're confused at first, mistakenly thinking there's nothing on here right now. Then we notice the crack in the floor and the small crowds of people peering inside. It's hardly the most impressive exhibit we'll ever see but I'm open to most things...not a good start for skeptical newcomers, however! We spend the next while perusing the permanent exhibitions; I'm happy as a bee flitting around the place...a few I liked:

• Magritte's joke comic strip "Man With a Newspaper"
• Meredith Frampton's super-realistic "Portrait of a Young Woman"
• Jackson Pollock's "Summertime: Number 9A"

There are also two temporary exhibitions in progress:

• A Juan Muñoz retrospective, with no less than 14 rooms containing his installations and sculptures. I wasn't sure about this at first at all, opening as it does with a collection of small iron sculptures, however I was quickly won over by "The Wasteland", an installation featuring a small bronze figure seated on a balcony over a patterned floor. Together with "Two Ballerinas", I was put in mind of David Lynch's uncanny ability to combine the absurd, the unsettling and the hilarious. "Many Times" is unsettling in a quite different way: comprising 100 figures with 100 identical heads but 100 different poses, the viewer is suddenly outnumbered by the exhibition. There are groups, cliques, loners, couples and unseen marvels on display here. We are part of the exhibition; we are excluded from the exhibition. For me, it is for some reason really remarkably and uncannily like I am back in Japan...a stranger in a friendly but alien and indifferent place...
• I'm less wowed by the Duchamp, Man Ray and Picabia exhibition but that's not saying much; I felt Muñoz was the best exhibition I've seen in a long long time. Here, I'm particularly taken by the early works. Names are sadly forgotten now, however one of them was Duchamp's "Nude Descending a Staircase".

Overall, a wonderful experience. The museum does have all the standard modern art clichés - huge canvasses painted red, unpainted framed canvasses with a hole cut through them and all that other stuff that was maybe fun the one time - but it has so much more, too: the surrealists, the minimalists, the futurists; the sculptures; the installations; brilliant colours and startling shapes. There's a little something for everyone and it would be hard work indeed to come away completely unsatisfied. If nothing else, you'll see the best modern art has to offer; make your mind up here.