Archaeologists have discovered a 2,600-year-old Assyrian palace beneath a shrine that was destroyed by ISIS in 2014.
According to ScienceAlert.com, the shrine and palace are in the Iraqi city of Mosul, which was under ISIS control until late January.
When state troops seized control of the area, local archaeologists informed them of the find and warned that the ancient palace -- which is filled with untouched artifacts and marble sculptures -- is in danger of collapsing in on itself.
"We fear it could all collapse at any time," said archaeologist Layla Salih to The Sun. "There are cave-ins in the tunnels every day."
Salih said that the palace belonged to King Esarhaddon, who ruled from 681-669 BC. It was discovered beneath the remains of the Nabi Yunus shrine, which ISIS forces destroyed with explosives in July of 2014 as part of their crusade to purge the region of any non-Islamic shrines, temples, sculptures or sacred relics.
Reverence for relics from the Greek and Assyrian period is considered "idolatry" under ISIS' fundamentalist interpretation of Islam.
The Nabi Yunus mosque was a grand 125th century mosque that was believed to contain the tomb of the Biblical prophet Jonah -- known as "Yunus" in the Quran.
After ISIS forces were driven from Mosul, Iraqi archaeologists were horrified at the damage to Nabi Yunus shrine.
Cultural Minister Salim Khalaf said the shrine was "far more damaged than we thought."
ISIS fighters dug tunnels under and around the shrine to hide in and to store weapons and supplies, honeycombing the area and making it potentially unstable. However, it was these tunnels that opened a passage to the ancient palace. Now it is a race against time to map the site and retrieve and catalog as many artifacts as possible.
ScienceAlert said, "More than 100 pieces of pottery were left behind by ISIS, accordingly to Salih, and reports of stunning white marble sculptures of winged bulls are one of the most exciting finds so far, along with elaborate bas-reliefs on the tunnel walls with inscriptions in cuneiform alphabet and sculptures of women's faces."
Sebastien Rey, lead archaeologist of the Iraq Emergency Heritage Management Program at the British Museum, told The Guardian, "The archaeologists are incredibly brave. They are working in extreme danger, with the mud brick in danger of collapse at any time."
He continued, "When it is safe to mount a full rescue excavation this will be a major operation, needing a great deal of resources which will certainly mean international support."
Check out some of the images here.