The west theatre was built out of basalt into the western slope of the acropolis at the southern end of the Cardo street and the Roman Terrace during a period of rapid urban expansion in the second half of the 2nd Century CE.
The auditorium (cavea) is made up of three tiers of seating divided into wedge-shaped seating sections by steps to allow the audience in and out of their seats and had enough space for about 3000 people.
Underneath the second tier a vaulted corridor (crypta) provides access from the street around the theatre to the upper tiers of the auditorium through four entrances (vomitoria).
"West Theatre at Umm Qais" by Ankur Panchebudhe is licensed under CC BY 2.0
The back wall inside the shops formed the foundation for the north south wall of the roman buildings on the terrace above and this wall was later re-used in the byzantine period when the terrace was converted to an ecclesiastical complex.
Following the collapse of many of the buildings of Gadara in the earthquake of 749CE, the terrace and cardo were buried and over time consolidated into a more natural slope on which buildings of the ottoman village were later added.
From 1995 archaeological excavation exposed the terrace, the cardo and the shops and lead to some reconstruction of the façade.