Sala Canal Isabel II by Rios Rosas metro in Madrid is a great example of an imaginatively re-purposed space. This beautiful water tower was built to deal with the poor the water pressure in this neighbourhood. It was made redundant by improvements in engineering and plumbing and so, what to do with such a pretty, domed tower?

Turn it into an uber-cool gallery space of course, which is what they did in 1986; one destined specifically for contemporary photography and audio-visual exhibitions. It’s perfect – walk round this beautiful space laid out on four levels and somehow it just makes sense. There is a small lift, if your legs are not up to the stairs, although you’ll have to go up into the dome by your own steam. This part of the building has been made into a small auditorium, where films are shown.

Do you need any more convincing? Well, it’s almost always empty, and it’s free! Also, it’s nice and cool in the summer. I went in there on a swelteringly hot day at the end of June and saw no one but a middle-aged couple, smooching in an alcove – it’s actually a great place for a rendezvous… It’s so hermetic too; when I left that day it felt like a slightly altered Madrid from the one I’d left when I’d gone in. Go on, step inside – I’m sure you’ll love it as much as I do!