清七地獄から道路の向こう側に、横断歩道を渡ると左手にゆるやかな登りの歩道が整備されています。
大宝元年（701年）開山の真言宗の寺院、雲仙山満明寺への参道です。（かっては、その歴史を伝える貴重な門柱「大宝元年開山・温泉山満明寺」があったのですが、残念ながら工事のときに撤去？されていまいました。）
雲仙山を開いたのは、奈良時代、東大寺の大仏造営（大勢の庶民が賦役で苦しみ、亡くなった）にも尽力した僧「行基菩薩」だと伝えられています。
ここ雲仙は、弘法大師空海開山の高野山や、天台宗の比叡山よりも100年も早く開山されており、日本三大霊場として栄えていました。雲仙山満明寺の上公園には、雲仙八十八箇所巡りがあり、その参道途中には行基立像があります。
　寺院の履歴書といわれる「縁起書」によると、文武天皇の命令を受けて建立され、最盛期にはお坊さんが住まれる住居「坊」が、3379坊もあったとされています。当時は、島原半島全域が温泉山を中心として仏教聖地として繁栄していました。

★英語バージョン
　Not long after the introduction of Buddhism to Japan, the wandering monk Gyōki came to Unzen and established a Buddhist temple on the mountain in 701. While the temple buildings and the other temples that built later were destroyed when Shimabara became a Christian domain in the late sixteenth century, Manmyōji is in direct lineage of that first temple.
　Inside is a massive 5-meter-tall daibutsu (statue of a buddha). It was completed in 1917 and is coated in five layers of gold leaf. Behind the temple, there are 88 unique statues, meant to represent a miniature version of the 88 Temple Pilgrimage on the island of Shikoku. Farther along, a large statue of Gyōki marks what is supposedly his grave.
　Gyōki lived during the Nara period (710–794) when the imperial capital had been moved to Nara, south of Osaka and Kyoto. In the century and a half since its arrival in Japan, the study of Buddhism had already spread across the country, thanks in part to the evangelism of Gyōki, who often raised funds for the construction of temples, statues, and other Buddhist structures. The temple’s history books claim that Gyōki was instructed to build this temple by the Emperor himself! During its use, as many as 3,000 monks lived in Manmyōji, where they meditated and studied the sutras. With this, Unzen’s reputation as a great center of Buddhist spirituality was secured.