The Tin Gate is believed to have been built during the time of Shimazu Mitsuhisa, the 19th head of the Shimazu family and the founder of Sengan-en.

Historically, passage through this main gate was strictly limited. Only the head of the Shimazu family and the designated heir were permitted to pass through it, underscoring the gate’s special status within the estate.

In the illustrated scroll “Sixteen Views of Sengan-en,” a small landing place known as Shitadashi is depicted. This scene suggests that the Shimazu lords once traveled to Sengan-en by boat from the castle town of Kagoshima rather than by land.

Tin, however, is not a metal commonly found in most parts of Japan. In contrast, Satsuma was unusually rich in tin deposits during the Edo Period, boasting the highest level of production in the country. The Tin Gate reflects its local abundance, highlighting it as a distinctive regional specialty.