On a recent visit to Barcelona, we stumbled upon a striking and mysterious building which I'd not read about before. El Museu Blau (The Blue Museum) is the new home of the Museum of Natural Science, although it was actually built as part of the controversial 2004 Universal Forum of Cultures. It was designed by Swiss architects Herzog & de Meuron, who are best known for the the conversion of the Bankside power station in London into Tate Modern. As we were heading for a nearby festival, we didn't have a chance to see inside – but I took a few snaps of Di & Ryland admiring the exterior.