Botanical Gardens (Acharya Jagadish Chandra Bose Indian Botanic Garden)

Established in 1787, this sprawling 109-hectare (269-acre) garden is home to the Great Banyan Tree, one of the world's largest trees by canopy coverage. The tree appears as a forest unto itself, with over 3,000 aerial roots covering approximately 14,500 square meters. The 250-year-old tree is a spectacular sight. The garden houses more than 12,000 different plant species and is believed to have helped establish the trade of tea in Assam and the Himalayan regions.

Location: Shibpur, about 4km south of Howrah Bridge
Entry: Rs 20 for Indians, Rs 100 for foreigners
Best Time: Early morning for birdwatching