Tate Britain

The building itself stops you dead on Millbank - all grand Victorian-era stone and formal gardens sweeping down to the Thames. Inside, you're walking through room after room of British art from the 1500s onwards, which sounds dry until you're actually standing in front of a Turner so luminous it makes everything else fade away.

You could spend three hours here or six, depending on what grabs you. The permanent collection is free, which is proper good value. The modern wing focuses on contemporary British work - some of it genuinely brilliant, some complete nonsense, but at least you get to decide. Families with teenagers who can manage a couple of hours on their feet will find plenty to hold attention; younger kids get bored fast in long galleries, no getting round that.

The cafe upstairs is decent and doesn't charge like they're serving gold leaf. If you're staying at Lovat Parks just down the road, you could easily pop in for an afternoon without making it your whole day. The river views from the garden level are worth lingering over, especially if the light's right.

Worth a visit if you've got a free morning and you're interested in what British artists were thinking - particularly strong on Romantic painters and the Pre-Raphaelites. Don't expect to be thunderstruck by every painting, but you'll find your thing.