The valley was the ancient capital city of the Khasa Kingdom and is considered a historically significant place.

Palaces, temples, and the ancient remains of a settlement were uncovered during excavations spearheaded by the Department of Archaeology at Cambridge University.

Major finds from the site include a large network of underground pipes that formed a complex water delivery system as well as a ring of massive monolithic stone columns circumscribing the settlement.

The Sinja Valley was where the Nepali language originates from and the earliest examples of the Devanagari script from the 13th century were found on the cliffs and in nearby Dullu.

[2] This site was added to the UNESCO World Heritage Tentative List on January 30, 2008 in the Cultural category.