Hirauchi Kaichu Onsen

Yakushima, one of Japan’s first UNESCO World Heritage sites, may be famous for Jōmonsugi, the 9,000-year old cryptomeria tree in the center of the island, but there are lesser-known treasures scattered along the island’s perimeter.

Hirauchi Kaichu Onsen aces the Sea of Japan on the southern coastline in Hirauchi village. Formed from ocean rocks, there are small onsen (hot spring) bathing pools inches from the sea. Bathing in this secluded onsen is one of Kagoshima prefecture’s hidden gem that is loved by local residents.

Public transportation in Yakushima is restricted to local buses, so it’s recommended to get a rental car, and make a pit stop here as you drive around the island. You can park at the top of the hill and walk down a short path to the onsen, where you’ll deposit as a small donation. The onsen itself is sulfuric, and the onsen water gives off a significant salty aroma, as it becomes mixed with ocean water during high tide. Sulfuric onsen are said to improve inflammation in the joints and improve pinched nerves.

It’s co-ed

Note that the sign outside of the minshuku (Japanese-style bed and breakfast) adjacent to the onsen explicitly states “no swimsuits allowed”. This is a mixed onsen, so don’t be surprised if others join you in the nude. Hey, it’s all about becoming “one with nature” when you’re as far out as Yakushima anyway! Enjoying being naked in nature is part of the onsen experience and is devoid of sexual connotations. The locals don’t mind the “skinship”, and neither should you.

You should check the tides, as the separate bathing areas are completely engulfed by ocean waves at high tide. The bathing areas are only accessible for a few hours in the evening. Your hotel will be able to tell you the times, and there are plenty of small minshuku in the area to stay in after you’re done watching the sunset from this gorgeous locale.

One caveat: the onsen is mixed with ocean water, so you may want to take a real bath/shower afterward. This particular onsen is less about getting clean and more about experiencing an abundance of Japan’s natural treasures. The view at sunset — or even in the moonlight — will leave you fully relaxed and refreshed.