As others have said, no much in way of explanations really

Construction began under Trajan  in the 2nd century AD and it was destroyed twice by earthquakes in the 6th and 10th centuries. It is the largest Roman amphitheatre ever built in the Balkan Peninsula, once having a capacity of 18- 20,000 people.

The amphitheatre was built in the beginning of the 2nd century AD, and was used for performances until the 4th century AD. The earthquake of 345/346 likely damaged the monument and closed the 'ludii gladiatorii'. An early Christian chapel was constructed on the amphitheatre in the second half of the 4th century. The chapel was initially decorated with frescoes; in the 6th century, mosaics were added.A medieval chapel was built in the 13th century, also decorated with frescoes. The amphitheatre was covered over in the 16th century, after the Ottoman occupation, when a wall was built nearby. Marin Barleti described the monument as 'well constructed'.

About one third of the site was discovered and excavated in the 1960s by Vangjel Toci; the rest was excavated in the 1980s by Lida Miraj. After excavation the amphitheater slowly deteriorated, as no conservation efforts were undertaken prior to the 2000s, and construction continued to take place around the site. In 2004, the University of Parma started restoration work to save the monument.