Context:

• UNESCO has included the ‘Diamond Triangle’, consisting of the Buddhist sites of Ratnagiri, Udayagiri, and Lalitgiri in Odisha, in India’s Tentative List of World Heritage Sites.

Odisha’s Diamond Triangle:

• It is a group of three major ancient Buddhist sites — Ratnagiri, Lalitgiri, and Udayagiri.
• These sites are located in the hills of Jajpur and Cuttack districts.

Meaning of the Name and Religious Significance:

• Vajrayana Buddhism: The name is derived from the Vajrayana branch of Buddhism, which literally means “Vajra Vehicle” or “Diamond Vehicle.”
• Confluence of Three Branches: The site represents the sequential development and history of the three major branches of Buddhism — Hinayana, Mahayana, and Vajrayana.

Details of Major Sites

Lalitgiri:

• Considered the oldest and most sacred site of the Diamond Triangle. Its history spans from the 2nd Century BCE to the 14th Century CE.
• Relics of Lord Buddha: During excavations (1985–1992), sacred relics were discovered from the Mahastupa. These relics were preserved in three-layered caskets made of gold, silver, and stone, the first discovery of its kind in Eastern India.
• Apsidal Chaitya: A massive brick prayer hall with a circular stupa at its center was found here — the first such Buddhist structure discovered in Odisha.
• Ancient Monasteries: Excavations revealed remains of four large monasteries where monks and students from across the world once studied.
• Art and Sculptures: Statues of Buddha in various postures, idols of Tara and Avalokiteshvara, and inscriptions in Kushan-Brahmi script have been found here.

Ratnagiri:

• The most grand and artistically rich site.
• Also known as the “Hill of Jewels.”
• A major global center of Tantric (Vajrayana) Buddhism between the 5th and 13th centuries CE.
• Carved Entrance Gateway: Famous for the intricately carved entrance of Monastery No. 1, made of green chlorite stone.
• Monastery Structures: Two massive monasteries and a large stupa have been found. It also has India’s only monastery with a curvilinear roof.
• Sculptures: Features an 8-foot tall Buddha statue surrounded by smaller Buddha figures and Buddhist deities. The sculptures show influence of Gandhara and Mathura art styles.
• Mention by Xuanzang: Chinese traveler Xuanzang described the spiritual importance of this Mahavihara.
• Museum: The ASI site museum displays thousands of small sculptures, terracotta seals, and copper plates found during excavations.

Udayagiri:

• The largest site of the Diamond Triangle in terms of area.
• Known in ancient times as Madhavapura Mahavihara.
• Two Major Complexes: Udayagiri-1 (Madhavapura Mahavihara) and Udayagiri-2. Excavations revealed large stupas, monasteries, and temples.
• Unique Step-well: A rock-cut ancient step-well showing advanced water management systems.
• Sculptural Richness: Large statue of Avalokiteshvara and Buddha statues in Bhumisparsha Mudra, along with tantric Buddhist carvings.
• Rock-cut Caves: Several small caves and inscriptions showing donations made by local kings.
• Natural Surroundings: Surrounded by green hills, making it ideal for meditation and peace.

Historical Timeline:

• Most monasteries were built between the 5th and 13th centuries CE.
• These centers flourished during the Bhaumakar dynasty (8th–10th century CE).
• Chinese traveler Xuanzang visited these regions in the 7th century and mentioned them in his travel records.

Tourism and Connectivity:

• Located about 90–100 km from Bhubaneswar and 60 km from Cuttack.
• Easily accessible via National Highways (NH-16/12).

About UNESCO

• Full Name: United Nations Educational, Scientific and Cultural Organization (UNESCO)
• Established: 1945
• Headquarters: Paris, France
• Objective: Promote peace and sustainable development through education, science, culture, and communication.
• World Heritage Convention: Adopted in 1972.
• World Heritage Day: Celebrated every year on 18 April
  • 2025 Theme: “Heritage at Risk from Disasters and Conflicts: Learning from 60 Years of ICOMOS Actions.”

UNESCO Tentative List:

• A list of properties that a country considers suitable for future nomination as World Heritage Sites.
• Works as a waitlist for the main World Heritage List. A site must remain on the tentative list for at least one year before nomination.
• Nomination Process: In India, the Archaeological Survey of India (ASI) identifies sites and submits details of their Outstanding Universal Value to UNESCO.
• Importance: Inclusion means international recognition of global cultural or natural significance.
• India’s Status:
  • 44 sites in the main World Heritage List (Latest: Maratha Military Landscape – 2025)
  • 70 sites in the Tentative List

Latest Three Additions to the Main World Heritage List:

• 44th: Maratha Military Landscape (2025) – Includes 12 important forts in Maharashtra and Tamil Nadu.
• 43rd: Charaideo Maidam, Assam (2024) – Burial mound system of the Ahom dynasty.
• 42nd: Sacred Ensembles of the Hoysalas, Karnataka (2023).