Tomb of Caecilia Metella (c-50). The Tomb of Caecilia Metella is a mausoleum located just outside Rome at the three mile marker of the Via Appia. It was built during the 1st century BC to honor Caecilia Metella who was the daughter of Quintus Caecilius Metellus Creticus, a consul in 69 BC, and wife of Marcus Licinius Crassus, son of the famous Marcus Crassus who served under Julius Caesar. The Tomb of Caecilia is one of the most well known and well preserved monuments along the Via Appia and a popular tourist site. In 2013, the museum circuit of the Baths of Caracalla, Villa of the Quintilii, and the Tomb of Caecilia Metella was the twenty-second most visited site in Italy, with 245,613 visitors and a total gross income of €883,344. Located on top of a hill along the Via Appia, the Tomb of Caecilia Metella consists of a cylindrical drum, or rotunda, atop a square podium with the Caetani Castle attached at the rear. The square podium stands at 8.3 meters tall with the cylindrical drum standing at 12 m. The monument in totality stands at a height of 21.7 meters tall. The diameter of the circular drum is 29.5 m, equivalent to 100 Roman feet. Further up the monument, decorations can be seen depicting festoons and bucrania, heads of bulls, which were the inspiration for the area being named Capo Di Bove, meaning head of the bovine. At the top of the monument, medieval battlements can be seen from the time when the tomb was used as a fortress. At the rear, the Caetani Castle is attached to the tomb. The castle originally was three levels: ground level, first level, and second level. It is unknown what the second level was used for but the first floor was used for the elite gentlemen as evidenced by fireplaces and refined goods. The castle is now used to display various decorations from the monument. The foundation of the Tomb of Caecilia Metella rests partially on tuff rock and partially on lava rock. The lava rock is part of ancient lava flow from the Alban Hills that covered the area 260,000 years ago. The core of the podium was cast in several layers of concrete, ranging from.7 to.85 m thick. The thickness of each layer corresponds with the height of the travertine facing blocks that surrounded the podium as the travertine was used as a frame in order to help the concrete layers form. The rotunda was built in this same fashion, travertine blocks on the outermost section with cement poured in the middle to give the concrete some structure and then covered in Travertine revetment, most of which has been stripped away. While the walls of the tower are 24 ft thick, comparatively the adjoining castle of the Gaetani was made of a thin wall of tufa. Originally the top of the monument would have been a cone shaped earthen mound as conical shapes were common with Roman rotundas but the earthen mound has long been replaced by medieval battlements. The Roman concrete was made up of semi-liquid mortar and aggregate, which consisted of broken pieces of stone or bricks. The aggregate was made up of rather large pieces of stone compared to modern cement which is finely ground to create a smooth, flat surface. Mortar and concrete were alternated in the construction as the semi-liquid mortar would bind the stone pieces together. The mortar used at this tomb utilized the lava rock beneath the monument as a substitute for sand in the concrete. The lava rock worked as well as sand and was more abundant versus the difficult to find sand. The interior of the Tomb of Caecilia Metella can be separated into 4 sections: the cella, the upper and lower corridors, and the west compartment. The most important being the cella which was used for funerary purposes and for housing the dead. The cella is a tall, circular shaft rising all the way through the center of both the podium and the rotunda. The cella is about 6.6 m in diameter at the bottom but tapers as it rises to a 5.6 m diameter at the top. The top features an oculus allowing for light. Throughout the cella, there are over 143 cut outs, divided into 12 rows of 10-14, in the walls of the cella that were used as putlog holes in the creation of the monument. The upper corridors is believed to be the main entrance to the cella. The upper section of the rotunda is decorated quite minimally with a marble frieze of bucrania, oxen heads, and garlands.