Built under the rule of emperor Trajan (98-117) the theatre was discovered unwittingly in 1972 during building site excavations. With seating capacity of 3 500, it hosts summer programmes of concerts and opera. The 28 rows of benches are set in a classic semi-circle facing the stage with three levels of colonnades. You are standing at the top of the "Water Hill ", so called because this was where drinking water was once distributed to the population.