The temple (known as a mithraeum), follows a typical plan of a narthex followed by the shrine proper that consists of a sunken central nave with podium benches on either side.

Trapezoidal in shape as the north end is wider than the south (5.50 m wide compared to 3.65 m), the shrine is 5.50 m long.

Two were dedicated by Septimius Justianus, a custodes armorum (a soldier in charge of the armoury) of Legio XIIII Gemina.

Lucius Avitus Maturus, decurion of the colony of Carnuntum, willingly deservedly happily fulfilled his vow.

Septimius Iustinianus, armorum custos of the 14th legion Gemina Antoninianae, willingly and deservedly fulfilled the vow.