The Kopai River (also called Sal River) is a tributary of the Mayurakshi River

Mayurakshi River

Mayurakshi River is a major river in West Bengal, India, with a long history of devastating floods.It has its source on Trikut hill, about 16 km from Deoghar in Jharkhand state. It flows through Jharkhand and then through the districts of Birbhum and Murshidabad in West Bengal before flowing...

. It flows past such towns as Santiniketan

Santiniketan

Santiniketan is a small town near Bolpur in the Birbhum district of West Bengal, India, approximately 180 kilometres north of Kolkata . It was made famous by Nobel Laureate Rabindranath Tagore, whose vision became what is now a university town that attracts thousands of visitors each year...

, Bolpur

Bolpur

Bolpur-Santiniketan is a municipality in Birbhum District in the state of West Bengal, India. It is 145 km north of Kolkata and is best known for the proximity to Visva Bharati, the university set up by Rabindranath Tagore the Nobel laureate poet...

, Kankalitala

Kankalitala

Kankalitala is a temple town in Bolpur subdivision of Birbhum district in the Indian state of West Bengal.-Geography:It is located about from Bolpur on the Bolpur–Labhpur road. It is situated on the bank of the Kopai River...

 and Labhpur

Labhpur

Labhpur , is a town with a police station in Bolpur subdivision of Birbhum district in the Indian state of West Bengal. Known to the outside world as the native place of Tarashankar Bandopadhyay, and located on the archaic narrow gauge railway, it is an extensive rural area subject to droughts in...

 in Birbhum district

Birbhum district

Birbhum district is an administrative unit in the Indian state of West Bengal. It is the northernmost district of Burdwan division—one of the three administrative divisions of West Bengal. The district headquarters is located at Suri...

 in the India

India

India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

n state

States and territories of India

India is a federal union of states comprising twenty-eight states and seven union territories. The states and territories are further subdivided into districts and so on.-List of states and territories:...

 of West Bengal

West Bengal

West Bengal is a state in the eastern region of India and is the nation's fourth-most populous. It is also the seventh-most populous sub-national entity in the world, with over 91 million inhabitants. A major agricultural producer, West Bengal is the sixth-largest contributor to India's GDP...

. It is a small river in dry season but overflows its banks during the monsoon.

Literary association

The area around the river quite often has red soil, which forms ravines on the river bank with weathering and is popular as the khoai

Khoai

Khoai in Bengali refers to a geological formation specifically in Birbhum, Bardhaman, and Bankura districts of West Bengal, India and some parts of Jharkhand, India that is made up of laterite soil rich in iron oxide, often in the shapes of tiny hills....

. It has inspired literary figures in the area. It is described by Rabindranath Tagore

Rabindranath Tagore

Rabindranath Tagore , sobriquet Gurudev, was a Bengali polymath who reshaped his region's literature and music. Author of Gitanjali and its "profoundly sensitive, fresh and beautiful verse", he became the first non-European Nobel laureate by earning the 1913 Prize in Literature...

 as follows –

amader chhoto nodi chale anke bankey
boisakh masey taar hantu jal thakey

Our small stream moves forward in bends and curves
In the month of Baisakh it only has knee deep waters

The local name of a sickle-shaped curve in the river inspired the title of the novel Hansuli Banker Upakatha

Hansuli Banker Upakatha

Hansuli Banker Upokotha is a novel by Tarashankar Bandopadhyay, made into a film in 1962 by Tapan Sinha starring Kali Bannerjee, Dilip Roy, Robi Ghosh and others. Set in 1941, the movie explores life in rural bengal, the realities of the Zamindari system that was responsible for much of the social...

(Story of the Sickle-shaped Curve) by Tarashankar Bandopadhyay

Tarashankar Bandopadhyay

Tarasankar Bandyopadhyay was one of the leading Bengali novelists. He wrote 65 novels, 53 story-books, 12 plays, 4 essay-books, 4 autobiographies and 2 travel stories...

, made into a film by Tapan Sinha

Tapan Sinha

Tapan Sinha , was a Indian film director. He was arguably the most uncompromising filmmaker outside the orbit of Parallel Cinema.-Personal life and background:...

.

Archaeology

Microlith

Microlith

A microlith is a small stone tool usually made of flint or chert and typically a centimetre or so in length and half a centimetre wide. It is produced from either a small blade or a larger blade-like piece of flint by abrupt or truncated retouching, which leaves a very typical piece of waste,...

s of crystalline stone and petrified wood from about 1250–1000 BC are found in many places in the Ajay

Ajay River

The Ajay River is a major river in Jharkhand and West Bengal. The word “Ajay” means “not conquered”.-Geography:The Ajay River originates on a small hill about 300 metres high, south west of Munger in Bihar. It then flows through Jharkhand and enters West Bengal at Simjuri, near Chittaranjan...

-Kunur

Kunur River

Kunur River , one of main tributaries of the Ajay, in length, has its origin near Bansgara in the Faridpur police station area. With water from several small streams swelling it during the monsoons, it often floods large areas of Ausgram and Mangalkot police stations of Bardhaman district...

-Kopai river system.