Plovdiv's fair opened in 1892 as an industrial and agricultural show and has outlasted every political arrangement Bulgaria has known since. It became permanent and international in the mid-1930s, joining the Union des Foires Internationales in 1936, and the present complex beside the Maritsa was laid out in 1948–49. Twenty-four pavilions stand on a site of some 360,000 square metres, with the largest exhibition capacity in south-eastern Europe; about forty shows a year pass through them. Between fairs the grounds serve the city as covered and open space for large public events.