fastest growing city in the world with a 31.1% urban growth between 2015 and 2020. It is a coastal city and on the banks of Ashtamudi Lake. The city hosts the administrative offices of Kollam district and is a prominent trading city for the state. The proportion of females to males in Kollam city is second highest among the 500 most populous cities in India. Kollam is one of the least polluted cities in India. During the later stages of the rule of the Chera monarchy in Kerala, Kollam emerged as the focal point of trade and politics. Kollam continues to be a major business and commercial centre in Kerala. Four major trading centres around Kollam are Kottarakara, Punalur, Paravur, and Karunagapally. Kollam appeared as Palombe in Mandeville's Travels, where he claimed it contained a Fountain of Youth. Etymology In 825 CE, the Malayalam calendar, or Kollavarsham, was created in Kollam at meetings held in the city. The present Malayalam calendar is said to have begun with the re-founding of the town, which was rebuilt after its destruction by fire. The city was known as Koolam in Arabic, Coulão in Portuguese, and Desinganadu in ancient Tamil literature. History As the ancient city of Quilon, Kollam was a flourishing port during the Pandya dynasty (c. 3rd century BC–12th century), and later became the capital of the independent Venad or the Kingdom of Quilon on its foundation in c. 825. Kollam was considered one of the four early entrepots in global sea trade during the 13th century, along with Alexandria and Cairo in Egypt, the Chinese city of Quanzhou, and Malacca in the Malaysian archipelago. It seems that trade at Kollam seems to have flourished right into the Medieval period as in 1280, there is instance of envoys of Yuan China coming to Kollam for establishing relations between the local ruler and China Pandya rule The ancient political and cultural history of Kollam was almost entirely independent from that of the rest of Kerala. The Chera dynasty governed the area of Malabar Coast between Alappuzha in the south to Kasaragod in the north. This included Palakkad Gap, Coimbatore, Salem, and Kolli Hills. The region around Coimbatore was ruled by the Cheras during Sangam period between c. first and the fourth centuries CE and it served as the eastern entrance to the Palakkad Gap, the principal trade route between the Malabar Coast and