Fact Check-Mumbai’s Gilbert Hill is a rock formation, not an ancient tree stump

Images of Gilbert Hill, a black basalt rock structure in Mumbai, India, are described falsely online as an ancient tree stump.

The reference relates to a conspiracy theory that the Earth is flat and remnants of giant prehistoric trees are evidence of an ancient world.

“Huge old world tree stump, in modern day Mumbai” read posts on Facebook (here) and messaging platform X, formerly known as Twitter (here) sharing images of Gilbert Hill.

However, Gilbert Hill is a monolithic columnar basalt stone formation, as noted (Page 8) in the minutes of a 2016 Mumbai heritage conservation committee meeting (here).

A study by Mumbai-based researchers presented at a 2008 conference in the U.S. also states “the rock type encountered in the Gilbert hill is mainly compact basalt” (here).

The study authors note that the hill “displays beautiful vertical columnar jointing,” which is rare, with “only two to three other such structures are present in the world” and that it was formed by volcanic eruption at the end of Mesozoic era about 65 million years ago.

The Geological Survey of India did not immediately respond to a request for comment.

Conspiracy theories have tied narratives of giant trees with an idea that the Earth is flat and “real” trees no longer exist (here).

Reuters has previously fact-checked similar claims about Devils Tower, a basalt rock formation in Wyoming (here) and (here).

VERDICT

Miscaptioned. Gilbert Hill in Mumbai is a basalt rock structure, not the stump of an ancient giant tree.

This article was produced by the Reuters Fact Check team. Read more about our fact-checking work (here).