The Amphitheatrum Castrense is a Roman amphitheatre next to the church of Santa Croce in Gerusalemme. It is dated to the first decades of the 3rd century AD. It was part of an Imperial villa complex which was built by emperors of the Severan dynasty. The open arches of the outer walls were walled up when the building was incorporated into the Aurelian Walls (271-275 AD), at which point it stopped being used for spectacles and began to be used as fortification, and the ground level around the building was lowered.
In the middle of the 16th century the remains of the second story were demolished for defensive needs. In the 18th century, a Hypogeum was found beneath the arena, filled with the bones of large animals. This leads researchers to believe that the spectacles here included Venationes, the hunting and killing of wild animals. Palladio and Étienne Dupérac made drawings about the ruins.
The building is a regular ellipse 88 meters long and 75.80 meters wide. It is constructed out of brick-faced concrete, with a few decorative elements in travertine. The structure was three stories high but only a section of the lowest story is preserved.
References:The stone church of Gamla Uppsala, built over the pagan temple, dates from the early 12th century. Due to fire and renovations, the present church is only a remnant of the original cathedral.
Before the arrival of Christianity in Sweden, Gamla Uppsala was the seat of Swedish kings and a ceremonial site known all over northern Europe. The settlement was home to royal palaces, a royal burial ground, and a great pagan temple. The Uppsala temple, which was described in detail by Adam of Bremen in the 1070s, housed wooden statues of the Norse gods Odin, Thor and Freyr. A golden chain hung across its gables and the inside was richly decorated with gold. The temple had priests, who sacrificed to the gods according to the needs of the people.
The first Christian cathedral was probably built in the 11th century, but finished in the 12th century. The stone building may have been preceded by a wooden church and probably by the large pagan temple.