Short answers, pulled from the story.
Sunder Nursery is a 16th-century heritage park complex covering 90 acres in Delhi, adjacent to Humayun's Tomb. It was originally a Mughal garden known as Azim Bagh and later repurposed as an experimental plant nursery during the British Raj. After extensive restoration, it reopened to the public on the 21st of February 2018 as Delhi's first arboretum.
Six structures within Sunder Nursery hold UNESCO World Heritage status: Sunder Burj, Sundarwala Mahal, Lakkarwala Burj, Mirza Muazzafar Hussain's Tomb, Chotta Bateshewala, and the Unknown Mughal's Tomb. The park contains fifteen heritage monuments in total.
Sunder Nursery reopened to the public on the 21st of February 2018. Restoration planning began in 2007 and the third phase of work was initiated in 2010. Vice-President M. Venkaiah Naidu and the Aga Khan attended the inauguration.
The restoration was led by the Aga Khan Trust for Culture India, jointly with the Archaeological Survey of India and the Central Public Works Department. Additional support came from the US Ambassador's Fund for Cultural Preservation and the Norwegian Agency for Development Cooperation, among other agencies.
Sunder Nursery earned the designation of Delhi's first arboretum because it contains over 300 types of trees, including more than 280 native species. Using GIS technology, researchers have mapped 4,200 individual trees in the park, including species such as the Pink Cedar found nowhere else in the city.
The rare Ultramarine Flycatcher was spotted at Sunder Nursery in 2014, a bird that had not been seen in New Delhi for many years. The park has around 80 species of birds identified through bird mapping, along with 36 varieties of butterfly.