Darwin's Arch natural bridge collapses in Galapagos Islands

May 18 (UPI) -- A rock formation in the Galapagos known as Darwin's Arch collapsed this week as the result of natural erosion, the Ecuadorian government announced.

The Ministry of Environment and Water said the natural bridge fell Monday, leaving only two upright pillars. The rock formation is located about half a mile southeast of Darwin Island, one of several islands in the Galapagos Archipelago.

It's named after Charles Darwin, the 19th century British biologist and naturalist whose field work in the Galapagos informed his evolutionary theory.

"This site is considered one of the best places on the planet to dive and observe schools of sharks and other species," the Ecuadorian Ministry of Environment and Water said in a Facebook post announcing the collapse.

Aggressor Adventures, a tour agency, said guests on one of its boat tours witnessed the arch's collapse, which it described as a "once in a lifetime event."

"Some in the dive & travel industry are already referring to this now as 'the Pillars of Evolution,'" the agency posted on Facebook. "We will miss this iconic site."