Lviv is the largest city in western Ukraine and is regarded as one of the main cultural centers of the country. The old heart of Lviv with its 19th century buildings and cobblestone roads survived World War II and then the Soviet occupation largely unscathed. There are many industries and institutions of higher education such as the Lviv University and the Lviv Polytechnic. Lviv is also a home to the philharmonic orchestra with its base in the beautiful Theatre of Opera and Ballet. The historic city centre is on the UNESCO World Heritage List. In September 2006 the city celebrated its 750th anniversary with much fanfare.