A decisive battle was fought on and around Yashima between the Taira and Minamoto clans in the Genpei War in the 12th century, when the Minamoto caused the Taira to flee by sea from their haven on Yashima by a ruse. The Minamoto were destroyed as a military force a month later at the Battle of Dan no Ura, with the stragglers taking refuge in the Iya Valley region of Shikoku.

Atop the plateau of Yashima is Temple No. 84 of the Shikoku Pilgrimage, Yashima-ji. The temple has a modern museum with artefacts from Yashima’s history. Other sights on Yashima are a monument to the Battle of Yashima and Chi no Ike or “bloody pond” where the victorious Minamoto washed their swords, turning it red with blood.

Just as Yashima looks remarkable from Takamatsu, the views from Yashima of Takamatsu and the Seto Inland Sea are likewise spectacular. Shops near the viewpoints around the mountaintop sell small clay discs, which are thrown off the mountain for luck, symbolizing the Minamoto warriors throwing off their helmets after their victory over the Taira.

Shikoku Mura, an architectural theme park, is located at the foot of Yashima. This open-air museum has a collection of traditional structures, gathered from all over Shikoku.