The church of Sant' Agostino was built by the Augustinian friars with the financial aid of Lucchese merchants around the middle of the XIV
th century, at the height of Pietrasanta's fortune when the town was indeed the economic capital of Versilia. The building has preserved entirely its XIV
th century structure with the exception of minor changes. The church has only one
aisle, its roof is supported by
trusses; the nave is closed by a rectangular
apse and today the only entrance is through a
portal with a lunette above. On the sides there was a door with a
round arch and three large brick
bifore that were closed, probably in the XVI
th century and replaced by four new quadrangular windows. The bell tower was built in 1780. The complex of Sant'Agostino is noteworthy for its dimensions and includes also a cloister and the homonymous convent to the east of the church, closed by Napoleon at the beginning of the XIX
th century.