Scientists explore a volcano, only to find it is a HIDDEN TEMPLE

EL Volcan is a temple, but its purpose remains a mystery.

In a lost Peruvian valley stands the cinder cone of an ancient volcano, complete with a caldera. Yet, there are no volcanoes near the cone and no evidence of volcanism. This mystery has prompted archaeologists to investigate the cone they call, "El Volcan." What they discovered has given rise to an enduring mystery.

LOS ANGELES, CA (California Network) -- They call it El Volcan because it looks like a volcano. First identified in the 1960s, archaeologists observed there were no volcanoes in the Nepena Valley where it was situated.

Archaeologists were in for a surprise. As they examined the mountain, they quickly realized it was not a volcano, but a mound. Further study revealed the shocking truth; El Volcan was a temple.

It's 50 feet tall, and scientists have little idea when it was built or why. Its proximity to a prehistoric civilization center suggests it was built between 900-300 BC.

Constructed as a pyramid, El Volcan has stairs, passages and floors coated with plaster. There's an ancient fireplace inside it. The fireplace seems to have been used as late as 1492-1602 AD.

There was also one more discovery awaiting the researchers. The site of the temple was also the location where four total eclipses occurred between the years of 1521 and 1543, which is virtually unprecedented.

Any spot on the Earth has a once in a 360-year probability of experiencing a total solar eclipse. To have four in less than 32 years is unheard of.

There is no way yet of knowing why the structure was built, or if it was built because of the eclipses. The Spanish began their conquest of Peru in 1532. The temple was probably in use during that time, but not for long afterward. It may have been covered by the people who used it to hide it from the Spanish. The Spanish had a tendency to destroy temples and to use their stones to build churches.

As for the crater, archaeologists think it could have been created more recently, the result of a collapse of the pyramid's center.

Nobody is sure of anything, other than the fact the pyramid was built by native people. Time and more study mat reveal the answers to these mysteries. Until then, we will wonder.