Sivasagar: Rang Ghar & Talatal Ghar

For nearly six centuries, from 1228 to 1826, the Ahom dynasty ruled the Brahmaputra valley — the longest unbroken rule of any dynasty in India — and repeatedly defeated Mughal armies, most famously at the naval Battle of Saraighat in 1671 under the general Lachit Borphukan. Sivasagar ('the ocean of Shiva'), named for the great tank at its heart, was their capital, and its monuments are among the finest historical sights in the Northeast.

The Rang Ghar, built in its present brick form in 1746 by King Pramatta Singha, is a two-storey royal pavilion from which the Ahom kings and nobles watched buffalo fights, wrestling and games — often described as one of Asia's oldest surviving amphitheatres. Its boat-shaped roof and elegant arches are built with a traditional mortar of rice paste, eggs and other organic materials, a signature of Ahom construction.

Nearby, the Talatal Ghar and Kareng Ghar form a great palace complex: a multi-storey structure with subterranean floors (talatal, 'below the ground') that once housed secret tunnels and escape routes. Together with the tanks, the Shiva temples around Sivasagar tank, and the newly UNESCO-listed Moidams at Charaideo a short drive away, Sivasagar is essentially an open-air museum of a forgotten empire.