Next time you're scurrying past the eastern end of St Martin in the Fields church in Trafalgar Square, linger a little longer over those windows.
Specifically, take a closer look at that arched central window, and you'll notice something amiss. The metal mouldings appear to have melted or warped, leaving a flat expanse of glass in the centre of the window.
It's almost as if Spanish Surrealist Salvador Dali has rendered his own interpretation of the 18th century church. Turns out it is art — albeit art by an Iranian-English team, rather than a moustachioed Spaniard.
The inventively-named East Window was designed by Iranian-born Londoner Shirazeh Houshiary and installed by architects Pip Horne Studio in 2008, as part of a £35m renewal of the entire church. The idea was to let in as much light as possible. It's not hard to imagine a pair of giant invisible hands pulling the glass asunder.
Oh, and if you're wondering what it looks like from the inside, here's the answer: