An ancient quarry where King Herod's workers chiseled huge high-quality limestones for the construction of the Second Temple, including the Western Wall, has been uncovered in Jerusalem, the Israel Antiquities Authority announced Sunday.

The quarry, which is located four kilometers northwest of the Old City of Jerusalem in the city's outlying Ramat Shlomo neighborhood, was used 2,000 years ago by dozens of King Herod's workers at the site during the construction of the Second Temple walls, archeologist Yuval Baruch said.

"This unique and sensational find is the first Second Temple quarry ever found," he said.

The site, which spans at least five dunams, was uncovered by chance during a "salvage excavation" carried out by the state-run archeological body over the last two months following municipal plans to build an elementary school in the area, he said.

Dozens of quarries have previously been uncovered in Jerusalem - including ones larger than the present find - but this is the first one that archeologists have found which they believe was used in the construction of the Temple Mount itself, Baruch said.

Archeologists had previously assumed that the quarry which was used to construct the Temple Mount was located within the Old City itself, but the enormous size of the stones found at the site - up to 8 meters long - as well as coins and fragments of pottery vessels dating back to the first century CE indicated that this was the site used 2,000 years ago in the construction of the walls of the Temple Mount, including the Western Wall.

"We have never found any other monument in Israel with stones this size except for the Temple Mount walls," Baruch said.

During the Second Temple period, the rulers of the city selected top quality stone in the construction of national public buildings that originated in the hard layers of limestone, referred to in Arabic as malakeh (from the Hebrew word malkhut or royalty) owing to its beauty and quality.

The quarry's pristine white rock, which resembles marble, and its huge, five-to-seven-ton blocks "are unprecedented and similar to those of the Temple Mount," he said.

The huge stones were likely transported to the area of the Temple Mount by horses, camels, or masses of slaves, Baruch said, noting that part of an ancient main road to Jerusalem which was used for the immense operation was recently uncovered just 100 meters from the site of the quarry.

The use of these enormous high quality stones during the construction of the Temple Mount compound is what maintained the stability of the structure over thousands of years, without requiring the use of plaster or cement.

The quarrying of each stone block was done in stages, according to Irina Zilberbod, the excavation director.

First, deep narrow channels were hewn around all four sides of the block, thereby isolating it from the surrounding bedrock surface. Then, using a hammer, the stonecutters inserted a row of cleaving stakes in the bottom part of the block until a fissure was created and the stone was detached.

A 5-kg. iron tool which was used by King Herod's workers - probably Jewish slaves - and was likely forgotten at the site was discovered intact beneath large stones in the middle of the excavations, Baruch said.

The site, which was used for no more than 20 years, was abandoned after the Second Temple period, said archeologist Ehud Nesher, who also took part in the dig.

The Second Temple was destroyed by the Romans in 70 CE.

The site where the quarry was unearthed is now surrounded by olive trees planted by Arab villagers, and a sprawling haredi residential neighborhood built over the the last decade.

The area of the quarry which has been uncovered is likely only 30 to 40 percent of its total size, but archeologists have no immediate plans to excavate the rest of the area because it is private property.

The discovery of the site comes as the state-run archeological body is immersed in a bitter controversy over recent Islamic infrastructure work on the Temple Mount itself, which independent Israeli archeologists say has damaged antiquities at Judaism's holiest site.

The work, which was authorized by the Prime Minister's Office, is meant to replace decades-old electrical cables at the ancient compound.

The Antiquities Authority, which has been repeatedly censured by the independent group of archeologists for failing to carry out proper archeological supervision on the Temple Mount due to the political sensitivites involved at the bitterly contested holy site, has repeatedly declined comment on the issue.