Situated in the southern part of the Plovdiv Plain, the city of Plovdiv developed historically atop seven hills, and is referred to in Bulgaria as the "city of the seven hills". The city is home to the International Fair Plovdiv, Bulgaria's largest and oldest international trade fair, which began in 1892. The fairground is one of the largest exhibition venues in southeast Europe and consists of 17 pavilions. Visitors to Plovdiv can also see one of the most famous monuments from antiquity in Bulgaria: the Antique Theatre. The Roman amphitheatre of Plovdiv was built in the 2nd century AD, and performances are held here in the summer months. Several other Roman sites can be found in Plevin, as well as monuments from other periods in history.