Hakone Kowakien Yunessun

A sprawling themed spa park that combines traditional Japanese onsen bathing with playful novelty pools. The swimwear zone features wine baths, green tea baths, coffee baths, and sake baths alongside waterslides and a Mediterranean-style pool, while the separate nude bathing zone (Mori no Yu) offers serene outdoor pools with mountain views. The combination of fun and relaxation makes this one of the rare onsen facilities accessible to families and those new to Japanese bathing culture.