The cubic structure of the temple has a square base of 32 x 32 m and was originally 23 m high. It stands on a 3 m high platform.

Facade
The facade was designed according to Greek models as a tetrastylos in antis: four columns stand between protruding wall sides (antae), which end in wider pilasters. The columns were 2 m in diameter and 15 m high. The stuccoed column shafts stood on a low plinth and Attic bases, and were crowned by capitals richly decorated with tendrils which supported an elaborate entablature (see the detail). On the front and the back of the temple, flat pointed gables preceded a surrounding attic (elevation of the wall beyond the edge of the roof).

Staircase
The representative open staircase across the full front of the facade has a wide landing after 19 steps. Eight more steps led through the columns into the prehall. The entire staircase was covered with marble slabs.

Pronaos
The space behind the columns was almost 29 m wide, about 9 m deep and 18 m high. In the two side walls there are large shallow niches with ornamentally decorated frames about 10 m above the floor. The walls were fully decorated with stucco imitating ashlars in the upper part. On the two front corner pilasters, a stucco decoration of square panels with alternating patterns of squares, octagons and circles is partially preserved. One can also see there fixing holes of lost stucco parts.