Gilbert Hill is the gigantic piece of rock you see practically in the middle of Andheri as you drive down Link Road near Juhu Circle. It might seem out of place because it actually is out of time and place: this 200-ft (61m) monolith column of black basalt rock dates back to 65 million years ago. That’s right, around the time dinosaurs roamed the earth! Fun fact: the Jainosaurus, a herbivore dinosaur of India and wider Asia lived around this time.
The rock has a sheer vertical face and was formed when molten lava erupted out of the Earth's clefts during the Mesozoic Era about 65 million years ago. During that era, molten lava spread around most of the Indian states of Maharashtra, Gujarat and Madhya Pradesh, covering an area of 50,000 square kilometres. The Kanheri Caves in Borivali and the Mahakali Caves in Andheri are made of the same black basalt rock. These volcanic eruptions were responsible for the destruction of plant and animal life and possibly even the dinosaurs during that era.
Atop the rock column there are two temples: the Gaodevi and Durgamata temples, which are set in a small garden. They are accessible by a steep staircase carved into the rock. The hill offers a panoramic view of suburban Mumbai.
In 1952, Gilbert Hill was granted National Park status. More recently, efforts from environmentalists and geologists resulted in making Gilbert Hill a Grade II Heritage structure. However, the hill is eroding and builders and slum dwellers are nibbling the area surrounding it over the years, even though quarrying and other activities around the monument are prohibited.
Gilbert Hill is often compared to the Devil’s Tower in Wyoming and the Devil’s Postpile National Monument in Eastern California, making it one of the 3 monuments of its kind left in the world.