The air currents between the sea and the mountain in St. Vlas create a unique natural phenomenon that purifies the air. The natural sea breeze in combination with the crystal-clear air creates conditions for sea balneotherapy and has a positive effect on patients suffering from asthma and other lung diseases. The favourable climate is suitable for year-round treatment. Sunny Beach is the largest tourist complex along the Black Sea Coast. With its hotels and apartment complexes located along the seashore and hidden in greenery, Sunny Beach looks like a magical oasis. The beach is 8 km long and 30 to 60 meters wide, covered with fine golden sand and natural sand dunes.