Sylhet

Sylhet (Bengali: সিলেট) is a metropolitan city in northeastern Bangladesh. It is the administrative seat of Sylhet Division. Located on the north bank of the Surma River at the eastern tip of Bengal, Sylhet has a subtropical climate and lush highland terrain. The city has a population of more than half a million, and is one of the largest cities in Bangladesh after Khulna, Chittagong and Dhaka.  Sylhet is one of the most important spiritual and cultural centres in Bangladesh. Furthermore, it is one of the most economically important cities in the country after Dhaka and Chittagong. The city produces the highest amount of tea and gas in the country.

In 1303, the Sultan of Lakhnauti Shamsuddin Firoz Shah conquered Sylhet by defeating Gour Govinda. Sylhet was a realm of the Bengal Sultanate. In the 16th-century, Sylhet was controlled by the Baro-Bhuyan zamindars and later became a sarkar (district) of the Mughal Empire. Sylhet emerged as the Mughals' most significant imperial outpost in the east and its importance remained as such throughout the seventeenth century. British rule began in the 18th century under the administration of the East India Company. With its ancient seafaring tradition, Sylhet became a key source of lascars in the British Empire. The Sylhet municipal board was established in 1867. Originally part of the Bengal Presidency and later Eastern Bengal and Assam; the town was part of Colonial Assam between 1874 and 1947, when following a referendum and the partition of British India, it became part of East Bengal. The Sylhet City Corporation was constituted in 2001. The Government of Bangladesh designated Sylhet a metropolitan area in 2009.

The hinterland of the Sylhet valley is the largest oil and gas-producing region in Bangladesh. It is also the largest hub of tea production in Bangladesh. It is notable for its high-quality cane and agarwood. The city is served by the Osmani International Airport which is named after General M A G Osmani, the Commander of the Bangladesh Liberation Forces. People from Sylhet form a significant portion of the Bangladeshi diaspora, particularly in the United Kingdom and the United States, as well as other countries in the Middle East.

Sylhet is located at 24.8917°N 91.8833°E, in the northeastern region of Bangladesh within the Sylhet Division, the Sylhet District and Sylhet Sadar Upazila. Sylhet has a typical Bangladeshi tropical monsoon climate (Köppen *Am*) bordering on a humid subtropical climate (*Cwa*) at higher elevations. The rainy season starts from April to October and it is so hot and humid with very heavy showers and thunderstorms almost every day, whilst the short dry season starts from November to February and it is very warm and fairly clear. Nearly 80% of the annual average rainfall of 4,200 millimetres (170 in) occurs between May and September.

The city is located within the region where there are hills and basins which constitute one of the most distinctive regions in Bangladesh. The physiography of Sylhet consists mainly of hill soils, encompassing a few large depressions known locally as "beels" which can be mainly classified as oxbow lakes, caused by tectonic subsidence primarily during the earthquake of 1762.

Geologically, the region is complex having diverse sacrificial geomorphology; high topography of Plio-Miocene age. Available limestone deposits in different parts of the region suggest that the whole area was under the ocean in the Oligo-Miocene. In the last 150 years three major earthquakes hit the city, at a magnitude of at least 7.5 on the Richter Scale, the last one took place in 1918, although many people are unaware that Sylhet lies on an earthquake prone zone.