Clifton Observatory and Camera Obscura
Originally a snuff mill, but destroyed in a gale in 1777, this great little tower was established by William West (a weird artist) who built a Camera Obscura on it. It's in a magnificent position, peering over the edge of the Avon Gorge and neighbouring the iconic suspension bridge. The projected, panoramic images of the view are something very special indeed. Mr West also cut out an underground passage from the tower to St. Vincent's Cave, which you can clamber down and look at 'DAN 4 LIZA' scribbled in this wonderfully historic place.