Udayagiri, the largest site in Odisha's Buddhist 'Diamond Triangle' with Ratnagiri and Lalitgiri

Background

In the news: the Archaeological Survey of India ordered private guards out of the protected Udayagiri Buddhist site, as reported on 10 October 2026.
Udayagiri, Ratnagiri and Lalitgiri form Odisha's Buddhist 'Diamond Triangle'; Odisha Tourism calls Udayagiri the largest Buddhist site in the triangle.
Udayagiri, in Jajpur district, stands on a crescent-shaped hill on the right bank of the Birupa; Ratnagiri, also in Jajpur, lies on the left bank of the Kelua, a distributary of the Brahmani.
Lalitgiri, in Cuttack district on the Nandapahad hillock, is the oldest site of the three.
The sites lie in the Assia hill range, and Buddhist activity there spans the 2nd–3rd century BCE to the 13th century CE.
India placed the 'Buddhist Triangle Sites of Odisha' on UNESCO's World Heritage Tentative List on 22 December 2025.