Deep Holes – Explorers find world’s deepest hole – Aug 9, 2004: “ZAGREB, Croatia (AP) — Cave explorers discovered a pit inside a mountain range in central Croatia believed to have the world’s deepest subterranean vertical drop, at nearly 1,700 feet, a scientific institute reported Monday.”

That is the world’s deepest natural hole. However, man has created a few much, much deeper:

On Russia’s Kola Peninsula, near the Norwegian border at about the same latitude as Prudhoe Bay, the Soviets have been drilling a well since 1970. It is now over 40,000 feet deep, making it the deepest hole on earth (the previous record holder was the Bertha Rogers well in Oklahoma–a gas well stopped at 32,000 feet when it struck molten sulfur).

I just love stuff like this.