An hour west of Tokyo, the lights of the city thin out, the hills darken, and then — abruptly, extravagantly — six million points of light bloom across a mountainside. Sagamiko Illumillion is what happens when an entire hillside amusement park surrenders itself to winter. You ride a ski lift up into the night, the glowing valley falling away beneath your feet; behind you, Lake Sagami keeps its darkness intact. The paradox is the point. Nowhere else so close to the capital do such deep country darkness and such dense artificial light share a single view. The season runs long here, from November into April, as if the park had decided that winter itself was the attraction. Children run through tunnels of light; couples drift up on the Ferris wheel to watch the patterns on the slope resolve into pictures, then descend to walk through the same lights at eye level. The cold on your cheeks at the top of the lift feels less like discomfort than part of the design. Tokyo is sixty minutes away. On a clear February night, it might as well be another country.