A large stalactite and stalagmite cave was recently discovered in an undisclosed location in the foothills of Jerusalem, it was announced Saturday.

Described as “huge,” the cave was discovered during construction occurring in the area. Officials of the Nature and Parks Authority are working alongside a team from Hebrew University’s Cave Research Unit to explore and map out the cavern.

The location is purposely being kept secret by authorities to make sure the public does not enter the cave before officials can determine how to preserve the ancient cave and its formations.

The use of secrecy when announcing such a rare geological find was used some 50 years ago when the world famous Avshalom stalactite cave, located outside Beit Shemesh, was first found. Some of the formations in the Avshalom cave date back 300,000 years.

“The first action we are taking in order to preserve the place is closing off the cave,” Uri Naveh, deputy head of the Nature and Parks Authority’s central district, told Walla! news. “That way we can maintain the humidity and the geological conditions which prevailed in the cave up until now with minimal interference.”

“Stalactites and stalagmites are a natural phenomenon protected by law,” Naveh explained. “That is why, at this stage, we will be barring entrance to the cave, other than for the researchers who will be entering to work there.”

Stalactites and stalagmites take thousands of years to form. Found in underground caves, the formations take shape from the slow drip of water and depositing of materials, usually limestone, over many years.

The newly discovered cave was found by chance when construction workers blasted open the side of a mountain. The same story applies to the Avshalom cave, which was uncovered in May 1968. The Avshalom cave covers an area of 5,000 square-meters. Some of the formations are as long as four meters and several of the stalagmites and stalactites have met, thereby forming stone pillars.