Varna is the largest city and seaside resort on the Bulgarian Black Sea Coast and the third largest city in Bulgaria. With approximately half a million inhabitants, it is the administrative centre of the homonymous province and Varna Municipality and the tenth-largest city in theBalkans. It is also the fourth largest city on the Black Sea. Sometimes referred to as the marine (or summer) capital of Bulgaria, though this has no official significance, Varna is a major tourist destination, a starting point for all the resorts in the northern Bulgarian Black Sea Coast, encompassing the so called Bulgarian Las Vegas - Golden Sands, business and university centre, seaport, and headquarters of the Bulgarian Navy and merchant marine. In April 2008, Varna was designated seat of the Black Sea Euro-Region (a new regional organization, not identical to the Black Sea Euroregion) by the Council of Europe. The Varna culture is a record holder, the oldest golden treasure in the world was discovered in Varna Necropolis, consisting of artifacts dating to 4750 BC. The city occupies 238 km2 (92 sq mi) on verdant terraces (Varna monocline of the Moesian platform) descending from the calcareous Franga Plateau (height 356 m or 1,168 ft) on the north and Avren Plateau on the south, along the horseshoe-shaped Varna Bay of the Black Sea, the elongated Lake Varna, and two artificial waterways connecting the bay and the lake and bridged by the Asparuhov most. It is the centre of a growing conurbation stretching along the seaboard 20 km (12 mi) north and 10 km (6 mi) south (mostly residential and recreational sprawl) and along the lake 25 km (16 mi) west (mostly transportation and industrial facilities). Since antiquity, the city has been surrounded by vineyards, orchards, and forests. Commercial shipping facilities are being relocated inland into the lakes and canals, while the bay remains a recreation area; almost all the waterfront is parkland. The urban area has in excess of 20 km (12 mi) of sand beaches and abounds in thermal mineral water sources.