Vintgar Gorge is walked a metre above its own river, on wooden galleries that have been bolted to the cliff since 1893. The Radovna fills the cut wall to wall for all of its 1.6 kilometres, so there is no floor to walk on and the entire route is carpentry. It lies four kilometres from Lake Bled, in Slovenia, and the oldest stretch, the Žumer Galleries, is pinned flat against the rock, carrying you out over the water and back again as the walls close in. The planks flex underfoot. The river runs a stride below, glassy and green where the current slackens, clear enough that you can count the stones on the bottom, and white wherever the channel pinches shut. Rock still comes off these walls, so they hand you a helmet at the entrance.
The Radovna has not always run through here. In the last ice age a glacier took its old valley and pressed the water against a ridge of limestone. When the ice withdrew, the river kept working the crack it had found, so this reads less like a valley than a slot cut downward. Noise announces the end of it. Šum means roar, and the sound fills the last stretch of walkway well before the water appears, coming down thirteen metres in a curtain. It is the largest river waterfall in the country, close enough to the platform that spray drifts over you when the Radovna is high. Directly above the falls a stone arch carries a railway line, built in 1904 and still in service. The gorge closes for the winter once snow settles on the planks, and in October, in the last weeks before that, the beech on the two hills it is cut between turns copper and gold above the water. None of this was built by a state or a railway company: the village of Gorje raised the money among its own households and spent two years putting the walkways in. The stretch pinned tightest to the rock still carries the name of the mayor whose village paid for it.