
This round ruin went from tomb to tollbooth. It still stands atop a hill along the Appian Way, about three miles south of the Colosseum. Originally over 70 feet tall and 96 feet wide, it had concrete walls 24 feet thick. As Piranesi noted on the tablet, it was built in the 1st century BCE to honor Caecilia Metella, “daughter of Roman consul Quintus Creticus and wife of Marcus Licinius Crassus.” The swallowtail-shaped battlements on top of the structure were added in the 1300s, when the tomb was converted into a fortress. The owners then used it to collect exorbitant tolls from travelers passing by on the Appian Way.