In the middle of Andheri, Mumbai, India stands a 66-million-year-old and 200-foot-tall monolith made entirely of black basalt. Known as Gilbert Hill, “the Hill” was formed during a volcanic lava spread during in the Mesozoic era in the Indian states of Maharashtra.

It is said that this basalt rock spread over 19,000 square miles, while Gilbert Hill is part of a ridge remnant extending through the state. This almost vertical column is considered similar to Devil’s Tower National Monument and Devil’s Postpile National Monument in Wyoming and California, due to similarities in its sheer rock face and basalt-rock composition. Most Mumbai city lovers consider The Hill as a well-kept secret in the middle of the urban sprawl, older than the trees and vegetation surrounding it.

For years, Gilbert Hill’s vertical columns—much like the Jogeshwari caves—was subject to quarrying as well as encroached on by housing built close to its base. In 1952, the Indian Central government declared Gilbert Hill a national monument and protected it from quarrying and housing development.