Plovdiv is one of the most important regions in Bulgaria both economically as well as for its rich cultural and historical heritage. Plovdiv's history spans some 8,000 years, with traces of a Neolithic settlement dating to roughly 6000 BC, making it one of the oldest cities in the world. Known for most of its history by the Greek name Philippopolis, it was originally a Thracian settlement before becoming a major Roman city. The city was known as Philippopolis in Western Europe well into the early 20th century. Plovdiv is among the few cities in the world with (two) Ancient amphitheatres, remains of the medieval walls and towers, Ottoman baths and mosques, a well-preserved old quarter from the National Revival period with beautiful houses, churches and narrow paved streets. The old quarter section embodies Plovdiv's long and varied history. The Greek Lucian called Plovdiv "the biggest and most beautiful of all towns" in Thrace. In addition to its ancient historical sites, there are numerous museums, art galleries and cultural institutions, and Plovdiv is host to musical, theatrical and film events.