Researchers hope the discovery would help them better understand the student days of famous Buddhist scholar Atish Dipankar Srigyan.
Sufi Mostafizur Rahman, a professor of archaeology at Jahangirnagar University, is leading the excavation.
“We have unearthed a Buddhist Vihara, an octagonal bulk, several brick-made drains, among others,” Rahman said.
He said the south-western side of the Vihara had survived the test of time.
According to Prof Rahman, the findings so far indicate that Nateswar was a cluster of Buddhist monasteries in the past. It was only natural to find Viharas beside it, he said.
The area was known as Bikrampur in ancient time and was the capital of Banga and Samataat communities between 980 and 1054 AD.
It was here that Atish Dipankar, child prodigy like Lord Buddha, was born during the regime of King Dharmapala (820 AD).
His fame had spread far and wide as the principal of Bikramshil and Sompur Viharas.
However, nothing much is known about his childhood and student days.
Prof Rahman said there are unanswered questions about Atish Dipankar’s childhood, like where did he take lessons in Buddhism and how he became a scholar?
“We believe the recently discovered Vihara has a deep connection with Atish Dipankar,” he said.
A 70-strong team, consisting of teachers, student and experts are taking part in the excavation under the Bikrampur Foundation, a local socio-cultural organisation.
Prof Rahman said they had discovered several important archaeological sites and artefacts since the survey and excavation started four years ago.
He said the recently discovered Buddhist Vihara segment was important as six rooms for monks had been found there so far.
The south-western part of the Vihara is still standing 2.4m high with a 1.75m thick wall.
The use of handmade designed bricks of various sizes in the construction has given it a wonderful architectural flavour, said the leading archaeologist.
Cultural Affairs Minister Asaduzzaman Noor, visiting the site on Friday, said, “This discovery will certainly add a new chapter in our glorious national history.”
Another ancient Buddhist Vihara was discovered in the Bikrampur region in March last year.