This strange, futuristic folly stands on the edge of Kielder Water in Northumberland. From the lake, it looks like a huge gift-wrapped megaphone, its curved surfaces reflecting the changeable shapes and colours of the mere and the sky. It is only from the landward side that the structure’s purpose becomes clear: it is a wedge-shaped hut (you enter via a narrow doorway at the back, as if stepping into a lift). The visor at the front is a window that frames the horizontal shoreline on the far side of the lake. You can stand inside and await the approaching ferry, or just hide here from the sheeting northern rain.