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 Broch of Clickimin is a large and well preserved, though somewhat restored broch near Lerwick. Originally built on an island in Clickimin Loch (now increased in size by silting and drainage), it was approached by a stone causeway. The water-level in the loch was reduced in 1874, leaving the broch high and dry. The broch is situated within a walled enclosure and, unusually for brochs, features a large 'blockhouse' between the opening in the enclosure and the broch itself. Another unusual feature is a stone slab featuring sculptured footprints, located in the causeway which approached the site. Situated across the loch is the Clickimin Leisure Centre.