Burgas (also transliterated as Bourgas; Bulgarian: Бургас) is the second-largest city on the Bulgarian Black Sea Coast. It is also the fourth-largest by population in the country, after Sofia, Plovdiv and Varna.
In the Middle Ages, a small fortress called Pirgos (Πύργος being Greek for "tower") was erected on the place and was most probably used as a watchtower. It was only in the 17th century that a settlement named Ahelo-Pirgas grew in the modern area of the city. It was later renamed to Bourgas and had only about 3,000 inhabitants, most of them Greeks at the time of the Liberation.
Soon it became a major center on the southern Bulgarian Black Sea Coast and a city of well-developed industry and trade. A number of oil and chemical companies were gradually built. Salt and iron are also mined and traded abroad.