Tatsukushi Marine Park & Minokoshi coastal walk

Ancient rock formations and Japan's first marine park

The Tatsukushi Marine Park and Minokoshi coast are part of the Ashizuri Uwakai National Park, located 8 kilometers west of the town of Tosashimizu. Both areas are known for sandstone and mudstone formations between 14 and 20 million years old, carved by wind and water erosion into unusual shapes. The ocean surrounding them is rich with coral reefs, and in 1970, this area was designated as Japan's first National Marine Park. Efforts are also underway to gain official Geopark recognition.

Walking the coast from Tatsukushi to Minokoshi

While it is possible to go directly to the beach formations from the nearest parking lot, we chose to follow a walk described on the Shikoku Nature Trail map website. Our walk, starting from the Tatsukushi coast, took about 4.5 hours with many stops along the way to take photographs. The trail is 7.2 kilometers one way, making it a 14.5-kilometer round trip.

Most of the walk is rocks and asphalt, except for the forest area in the Minokoshi Chihiro Peninsula, where we descended and ascended to the beach. Given the uneven terrain of the beach and rock formations, non-slippery walking or hiking boots are recommended. For those who prefer not to hike the entire distance, boat tours are available that provide a brief visit to the peninsula and allow for some exploration on foot.

Lunch at Tatsuya

We arrived just in time for lunch at Tatsuya, a family-run restaurant that closes at 3 p.m. The husband and wife who run it served us coffee at the end of the meal. We had the katsuo tataki set (seared bonito), a generous portion for 1,100 yen.

Ashizuri Underwater Aquarium

Update: the aquarium has been closed since May 2026 due to safety concerns over its deteriorating connecting walkway, and the operator hasn't set a reopening date. Check the official website before planning a visit.

When we visited, the entrance fee was 900 yen. The structure, built in 1971, stands 24.3 meters tall and sits 54 meters offshore. A circular staircase leads down to an underwater observatory 7 meters below the surface, where round windows look out onto tropical fish moving through the reef.

Other activities in the area

Other attractions in the area include the Ashizuri Aquarium (高知県立足摺海洋館 SATOUMI) and the Seashell Gallery (海のギャラリー). Nearby options also include scuba diving and glass-bottom boat trips. The Visitor Center has maps and information on the marine park and its trails.