Kappa Tengoku is a small onsen in Hakone. While it’s not particularly famous or well-known compared to other onsen in Hakone, it’s in a prime location. It’s less than a 5-minute walk from Hakone Yumoto Station, making it the perfect place to squeeze in a soak in a hotspring before heading back to Tokyo.
There is also a footbath near the entrance, if you’re not in the mood for the full onsen experience. The footbath uses an honor system, so just place the fee (¥200 for adults, ¥100 for children) in the payment box.