Seaside resorts The Bulgarian Black Sea Coast is picturesque and diverse. White and golden sandy beaches occupy approximately 130 km of the 378 km long coast. The temperatures during the summer months are very suitable for marine tourism and the water temperature allows sea bathing from May to October. Prior to 1989 the Bulgarian Black Sea coast was internationally known as the Red Riviera. Since the fall of the Iron Curtain, however, its nickname has been changed to the Bulgarian Riviera. Hiking and skiing The country has several ski areas which offer excellent conditions for skiing, snowboarding, ski running and other winter sports. National Parks Bulgaria has 3 national parks, 11 nature parks and 55 nature reserves. The first nature park in Bulgaria and the Balkan Peninsula is Vitosha Nature Park, established in 1934. Caves and waterfalls As of 2002, there are around 4,500 discovered underground formations in Bulgaria. The earliest written records about the caves in Bulgaria are found in the manuscripts of the 17th century Bulgarian National Revival figure and historian Petar Bogdan. The first Bulgarian speleological society was established in 1929. The caves in the country are inhabited by more than 700 invertebrate species and 32 of the 37 species of bats found in Europe. Nature landforms and formations Statistics Arrivals by country Most visitors arriving in Bulgaria on short-term basis came from the following countries of nationality: See also List of World Heritage Sites in Bulgaria References External links Official Bulgaria tourism website Bulgaria