Kanpuzan Rotating Observatory

Kanpuzan is a lava dome at the neck of the Oga peninsula, 355 metres high and covered entirely in grass — no trees, just a smooth green cone that looks like it has been mown. On top is a tower whose fourth floor rotates, completing a turn in about thirteen minutes, so that you sit still and the view moves: the peninsula, the Sea of Japan, the Ogata polder where Japan's second-largest lake used to be, and the Dewa mountains.

The grass is not natural — it has been maintained by burning for centuries for pasture — and walking the dome is as much of the attraction as the tower. The observatory opens from mid-March to early December and closes for the winter, which given that this is a bare hill in a snow region on the Sea of Japan is not surprising. Admission is ¥550.