Temples were impressive buildings which gave the town a striking appearance. They were built on a high plateau to dominate the entire surrounding area. They were accessible by stairs. Temples were used by priests and other temple servants to perform the standard rituals in Roman religion. As more temples were built outside the towns, the practice of performing religious rituals spread throughout the provinces, thus contributing to the process of Romanisation.

The most striking part of the Roman and Greek temple was the column. A column always consisted of a shaft, a capital and sometimes a base, depending on the order of architecture. The Greeks knew three orders: Doric, Ionic and Corinthian. The Doric column consisted of a shaft with drums and a capital. The capital consisted of two parts: an 'echinus'('in the shape of a cushion') and above it an 'abacus' ('in the shape of a block').

The Ionic column dates back to a later stage of development. In contrast to its predecessor, the Ionic column had a base and the capital was made of one piece.

The capital of an Ionic column was called a 'voluten' or 'curly' capital.

The Corinthian column finally, only differed from the Ionic column with regard to the capital. The Corinthian capital is a so-called 'acanthus' capital. 'Acanthus' is the Greek word for hogweed.

At first Roman temples were built in the Ionic order, but gradually the Romans developed their own order of architecture, the 'composite column', which is a mixture of Ionic and Corinthian elements.
On the abacus rested the architrave, the main stone or marble beam supporting the roof. Above the architrave came the frieze, a decorative band running continuously along the entire temple. In Roman times, however, the frieze had almost ceased to contain any ornaments. On the frieze, at the short end of the temple, rested the triangular front (fronton or tympanum).

The temples of the Greeks and Romans were architectural masterpieces. Already in that time builders were aware of the effects of optical illusions. If a column were to be completely straight it would, from a distance, be perceived by the human eye as being hollow. In order to avoid this effect the Greeks, and later the Romans as well, made sure the columns were somewhat convex. For similar reasons the columns in a colonnade were placed slightly outwards and the base was made a bit spherical too. In this way the problem of drainage was also taken care of.

Some of the major differences between Roman and Greek temples:

• Roman temples were built on an elevated plateau, with a big staircase in front. This in contrast to Greek temples which were built on a stylobate, a base of three steps.
• It is obvious which side of a Roman temple is the front side. This is not at all clear with Greek temples.
• The Greeks placed the statue of a god in the cella (a room in the temple that nobody was allowed to enter). The Romans mostly placed the statue in the absis.
• In contrast to the Greeks, the Romans used pilasters (half columns)
• Roman temples are monopteral, meaning they have only one colonnade, whereas Greek temples can be both monopteral as well as dipteral (having a double colonnade).
• Roman temples had columns on the front side only.