Some astrological signs and symbols of the Roman Religio were represented in the structure of the circus : the arena was the Earth, the Euripos the Sea, the obelisk was the symbol of the Sun, the twelve carceres were the constellations of the Zodiac, the seven laps which the chariots ran were the orbits of the seven planets, and so on. And, on the other hand, many aspect of the games cannot be comprehended if their religious origin is forgotten.

Giuseppe De Finetti, in his study called "Stadi.Esempi, Tendenze, Progetti. (Milano, 1933)" (Stadiums. Examples, Trends, Projects.) underlined at the very beginning, the survival of ancient shapes in this kind of constructions: " the study of the formal reasons of the modern stadiums connect us to the examples of two mediterreanean peoples, the Greeks and the Romans, who in this field arrived to the creation of definitive structures and models, survived over the centuries, typical for their astonishing harmonies between necessity and shape".

• arena: a race track with earth or sand with a long shape. According to Pliny, its length should be of three stadiums, one in width (Naturalis Historia, 24, 102).
• euripus: a channel to protect the audience, inserted around the arena field from the age of Caesar (the name comes from Euripos, Greece, the most famous channel in the ancient times, between Eubea and Beotia).
• spina, made with ground or masonry, which divided in two, most of the length of the arena. On the spina some decorative elements could stand, as obelisks, fountains, statues, little shrines, substructures for seven big stone eggs or seven bronze dolphins; they were used to count the laps of the race. The spina was not perfectly parallel to the long sides of the circus, so that the race could have the same length for all the players, both who ran inside or outside on the track.
• metae: half circular basis at the two ends of the spina, where chariots turned during the race.
• carceres: standing on the shortest side of the circus, they were used for the chariot to wait for the beginning of the race; they were formed by a six elements group, each one on one side of the monumental entrance; they were situated on a semicircle line (slightly slanting) so that the chariots standing in the outer lines were not disadvantaged.
• two towers: reserved to editores spectaculorum , referees and organizers of the races
• porta triumphalis: destined to the entrance of the pompa, the initial parade of the games. The gate was in the middle of the short and curved side.
• porta libitinaria: on one of the two more length sides, it was reserved to the transportation of the dead or wounded charioteers.
• cavea: the place where the audience was, divided by aisles where the acceding staircases led; they were on the long sides and on the opposite curve of the carceres. The stairs of the cavea were on different levels, divided horizontally by praecinctiones, and vertically by scalaria (stairs).
• pulvinar: a stage on an elevated position, hosting the deities statues to whom ludis were offered.

The stadium had a very similar shape with the circus; but it was destined to the athletics games and basically for the most famous of athletic sports (pentathlon). The track had an average length of 600 foot (584 modern foot = 178 mts); this measure was called for this reason a "stadium", even if different for almost each region.

The stadium also had shorter dimensions than a circus and it had not a spina and the carceres.

The hippodrome had again a shape similar to the one of the circus, with usually average dimensions greater than that. It was generally destined to a private use. From an architectural point of view, it did not follow structural guidelines. Usually a garden was used in the center to be used as a spina.

N.B. In the list are included also those circuses which the only remain is an obelisk, as they were used as spinae in many arenas