Servian Wall
Situated on the edge of Villa Celimontana and next to the Arch of Dolabella (Porta Caelimontana), a gate in the original Servian Wall, the church is dedicated to St. Thomas the Apostle. It is built into the side of the Claudian Aqueduct, from which comes "in formis" ("forma claudia" is Latin for the Claudian Aqueduct).