Metropol Parasol (Las Setas)
What is it?
Officially called Metropol Parasol but universally known as Las Setas ('the mushrooms'), this is the largest wooden structure in the world. Designed by German architect Jürgen Mayer, it was completed in 2011 and the building inspires equal amounts of love and hate.
Why go?
Look under the huge birch umbrellas and you'll find an excellent produce market (with a couple of cafés), a museum of Roman and medieval finds (discovered during construction), but the biggest draw is the fabulous view from the rooftop walkways.