This art instillation called Bridge, by Michael Cross, was part of last year's London Design Festival. The setting is an old church filed with 60 inches of water. As you approach the water you are met by one single stepping stone. Stepping out onto the stone causes a series of small platforms to rise out of the water creating a walkway. As you walk out to the center of the church, the steps disappear behind. You end up peacefully alone above the water, free to take in your surroundings. Sounds wonderful.
Unfortunately, based on people's Flickr photos it looks like the insurance company stepped in and added lifejackets and an escort to the mix as well as cutting out the disappearing steps. The effect isn't quite the same. (Found through Computerlove).