This is pretty cool.

Scientists report that the Lost City, a bizarre cluster of limestone spires rising from the peak of an ocean-floor mountain, is at least 30,000 years old.

The "city," on top of a mountain about as high as nearly 3-mile-high Mount Rainier, was discovered in 2000 by an expedition using a research submersible designed for deep-ocean diving. It was named for its towers, some as tall as an 18-story building.

The Lost City is about 4,500 feet deep, at 30 degrees latitude in the mid-Atlantic, 9 miles from the mid-Atlantic ridge. The ridge is where the North and South American continental plates have been separating from the European and African continents for about 20 million years. They are spreading at a rate of about 2 inches a year, creating the ridge between the plates.