
Awashizenmura Onsen (安房自然村) is a rustic hot spring facility located on the southern tip of the Boso Peninsula in Chiba Prefecture. Part of a larger ryokan complex that emphasizes nature-themed stays, the onsen is best known for its unique hillside aesthetic. A dramatic cave-like tunnel leads from the exterior into the mountain, though it is important to note that this specific entrance is typically reserved for overnight guests; day visitors are usually directed through a separate entrance near the restaurant area.

While the exterior provides an adventurous first impression, the facilities themselves are quite simple and dated. The bathing area consists of two small pools: a scalding indoor bath that frequently reaches temperatures of 45-46°C, and a more temperate outdoor bath kept at roughly 38°C. The “open-air” bath is set deep within a concrete and soil enclosure, offering a secluded but limited view of the surrounding trees. Despite the aging infrastructure and basic changing rooms, the facility remains a popular stop for those touring the coastline by motorbike or car, particularly due to the quality of the on-site dining.


| Visitor Information | |
|---|---|
| Address | 1101-1 Ito, Tateyama, Chiba 294-0305 (Google Maps) |
| Opening Hours | 10:00 AM – 9:00 PM (Last entry 8:00 PM) |
| Price | Onsen Only: ¥700 / Lunch + Onsen Combo: ¥1,500 |
| Website | Visit Website |
| Access | ||
|---|---|---|
| Station / Stop | Line / Bus | Access Details |
| Tateyama Station | JR Uchibo Line | Take the JR Bus toward Nojimazaki Lighthouse (approx. 25 mins). |
| Awashizenmura | JR Bus | The ryokan is located immediately adjacent to the bus stop. |