Mikurigaike Pond Loop, Murodo

The Mikurigaike Pond Loop circles Japan's highest-altitude crater lake at roughly 2,405 m, on the volcanic plateau above Murodo Station in the Tateyama Kurobe Alpine Route, Toyama. The loop begins directly outside the Murodo terminal building, reachable by cable car and highland bus from Tateyama Station in about an hour; no permit is required. The 2.1 km circuit gains almost no elevation, following a mix of paved walkway and raised boardwalk around the pond's rim, with volcanic gravel underfoot on short stretches near the Jigokudani steam vents. The plateau is fully exposed to sun, wind, and afternoon cloud, with little shade anywhere on the route. Key landmarks include the Mikurigaike Visitor Center at the start, the sulfurous vents of Jigokudani (viewed from a distance for safety), and viewpoints looking toward Mt. Tateyama's Oyama, and Onanjiyama peaks. Most walkers complete the full loop, though the visitor center side offers an easy turn-around point for a shorter out-and-back. Water and restrooms are available at the Murodo terminal and the visitor center, and the Murodo mountain hut sits a short walk from the trailhead for shelter in poor weather. Because the route sits above 2,400 m, temperatures can drop sharply even in midsummer, and the boardwalk can ice over outside the June-to-October window when the alpine route itself is open to the public.