Bulgaria has a rich cultural and natural heritage with many notable World Heritage sites. These include the medieval Rila Monastery, rock-hewn churches of Ivanovo, ancient city of Nessebar, Pirin National Park, and Thracian tombs decorated with well-preserved murals. Bulgaria also protects important natural areas like the Srebarna Nature Reserve and has other cultural sites such as the Tsarevets Stronghold in Veliko Tarnovo and the Alexander Nevsky Cathedral in Sofia.