The Naruto whirlpools form in the Naruto Strait between Shikoku and Awaji Island, where the tides of the Seto Inland Sea and the Pacific meet. At their strongest, the whirlpools can reach about 20 metres across. Sightseeing boats approach them, and a glass-floored walkway under the Ōnaruto Bridge lets visitors look straight down on them.

Ritsurin Garden in Takamatsu is one of the finest traditional gardens in Japan. It was developed over more than 100 years by local lords from the 17th century. Six ponds and thirteen small hills are set against Mount Shiun. Carefully shaped pine trees, bridges and tea houses fill the garden. Boats are available on its South Pond.

Naoshima is an island in the Seto Inland Sea famous for contemporary art. Since the 1990s the Benesse company has built museums, many designed by Tadao Andō, such as the Chichū Art Museum, set into a hillside. Outdoor artworks include Yayoi Kusama's yellow and red pumpkins by the sea. Art houses fill old buildings in Honmura village.

Kotohira-gū, also called Konpira-san, is a Shinto shrine on Mount Zōzu in Kagawa, dedicated to the guardian god of sailors and seafarers. Reaching the main hall requires climbing 785 stone steps, and the inner shrine is at 1,368 steps. Shops selling sweets and souvenirs line the lower steps. Views from the top reach the Seto Inland Sea.

The Iya Valley is a remote mountain valley in western Tokushima, cut by the Iya River. It is famous for its vine bridges, made of mountain vines, said to have been built so they could be cut down quickly if enemies came. The Iya Kazurabashi is about 45 metres long. Deep gorges, small villages and onsen fill the valley.

Kōchi Castle was first built in the early 17th century by Yamauchi Kazutoyo. Its keep and main palace, rebuilt in the 1740s, survive in their original form, the only castle in Japan where both remain. The castle stands on a hill in the centre of Kōchi. A Sunday market, held for over 300 years, runs along the street below.

Matsuyama Castle stands on Mount Katsuyama in the centre of Matsuyama. It was built from 1602 by Katō Yoshiaki. Its keep, rebuilt in 1854, is one of the twelve original castle keeps in Japan. A ropeway and chairlift climb the hill. From the top there are views of the city and the Seto Inland Sea.

Dōgo Onsen in Matsuyama is one of the oldest hot springs in Japan, said to be over 3,000 years old. Its main bath house, the Honkan, was built in 1894 and is a three-storey wooden building with a red heron on its roof. It is said to have inspired the bath house in the film Spirited Away. Visitors can bathe and rest in its tatami rooms.