The hill rising above Chowrasta is home to several much-visited temples, approached through a flurry of colourful prayer flags and hanging bells. The main summit temple is sacred to Mahakala, a Buddhist protector deity also worshipped as a wrathful avatar of Shiva. It is staffed by a Hindu priest and Buddhist lama sitting side by side in an admirable display of religious coexistence. A 300m path up to the summit starts about 100m along the eastern Mall road from Chowrasta.
The several other temples around the hilltop include a narrow cave with a Shiva lingam, signposted down steps to the left as you approach the summit. Sadly no mountain panoramas from the top, but if you go back down to the Mall and turn left (north) you'll soon reach a couple of viewpoints with Khangchendzonga-view benches.
Observatory Hill was the original location of Bhutia Busty Gompa, whose monks may have given Darjeeling its name calling their site dorje-ling (place of thunder).