The island of Rhodes is shaped like a spearhead, 79.7 km (49.5 mi) long and 38 km (24 mi) wide, with a total area of approximately 1,400 square kilometres (541 sq mi) and a coastline of approximately 220 km (137 mi). Limestone is the main bedrock. The city of Rhodes is located at the northern tip of the island, as well as the site of the ancient and modern commercial harbours. The main air gateway (Diagoras International Airport, IATA code: RHO) is located 14 km (9 mi) to the southwest of the city in Paradisi. The road network radiates from the city along the east and west coasts. Outside of the city of Rhodes, the island is dotted with small villages and spa resorts, among them Faliraki, Lindos, Kremasti, Haraki, Pefkos, Archangelos, Afantou, Ixia, Koskinou, Embona (Attavyros), Paradisi, and Trianta (Ialysos). There are mineral-rich spring water (and sometimes sea water) used to give medicinal baths and the spa resorts offer various health treatments. Rhodes is situated 363 km (226 mi) east-south-east from the Greek mainland, and 18 km (11 mi) from the southern shore of Turkey.