I was hanging around London with a mate today, it was great, we went to quite a few different places including the Rain Room at the Barbican, Angel, a Turkish Mosque and a few other places around Hackney. I really loved the Rain Room (despite the long wait!) I'd recommend a visit to anyone living in London. It sort of reminded me of the Yohji Yamamoto exhibition that was on at the Wapping Hydraulic Power Station... I've included some info below from the Barbican Centre website.
Random International invites you to experience what it’s like to control the rain. Visitors can choose to simply watch the spectacle or find their way carefully through the rain, putting their trust in the work to the test. More than the technical virtuosity necessary for its success, the piece relies on a sculptural rigour, with the entire Curve transformed by the monumental proportions of this carefully choreographed downpour and the sound of water.