Church where you can walk on water

Via Boing Boing:

Artist Michael Gross flooded a London church-turned-gallery with water. The "lake" hides a system of mechanically-moving steps that enable visitors to walk on water. The installation, titled Bridge, is up until October 29 at Dilston Grove.

From the gallery's description:

Each step emerges one step in front of you and disappears back underneath behind you as you go. This ‘bridge' is purely mechanical, the weight of the person on it depresses each step a little, this force activates a submerged mechanism which raises the next step.