Nii-jima Onsen is a popular hot spring located on Nii-jima, an island in the Izu Islands of Japan. Known for its beautiful coastal views and natural mineral-rich waters, the onsen offers visitors a relaxing experience. The hot springs are believed to have therapeutic properties, making them a favorite among locals and tourists alike. The onsen features various bathing options, including indoor and outdoor baths, allowing guests to enjoy the scenic surroundings. Nii-jima is also accessible by ferry, making it a convenient getaway for those looking to unwind in a tranquil setting.