Archaeologists have unearthed 20 intact ancient coffins near the Egyptian city of Luxor, the country’s antiquities ministry announced this week in a statement lauding the find as “one of the largest and most important” in recent years.

According to CNN’s Oscar Holland and Taylor Barnes, researchers discovered the coffins in Al-Assasif, a necropolis on the Nile River’s West Bank. Once part of the ancient Egyptian capital of Thebes, the site stands in what is now Luxor.

As Lateshia Beachum reports for the Washington Post, the coffins—decorated in shades of red, green, white and black—were found stacked in two layers in a giant tomb. The wooden sarcophagi are particularly impressive due to their colorful, well-preserved paintings and inscriptions, as well as the fact that they are still sealed—a rarity in Egyptian archaeology.

Although the antiquities ministry did not specify what time period the sarcophagi date to, BBC News notes that the majority of tombs in the necropolis hold the remains of nobles and government officials buried during Egypt’s Late Period, which lasted from 664 to 332 B.C.

There are, however, some exceptions to this trend: namely, tombs dating to the earlier 18th dynasty. Spanning the period of 1543 to 1292 B.C., this royal line included such pharaohs as Ahmenhotep I, Tutankhamun, and Hatshepsut, the so-called “queen who would be king.”

For now, information on the find remains scarce, but as a ministry statement notes, more details will be shared at a press conference this Saturday.

The cache of coffins isn’t the only recent find to come out of Luxor. Last week, archaeologists announced the discovery of an ancient “industrial” zone in the Valley of the Monkeys, a sprawling site neighboring the famed Valley of the Kings.

According to a government statement, the team unearthed 30 workshops, many featuring pottery dating to the 18th dynasty. Each shop had a different purpose—for example, producing pottery or gold artifacts—but all were assigned to the general task of creating funerary goods for Egyptian nobles and wealthy individuals. In addition to these workshops, the researchers found an in-ground water tank that likely held workers’ drinking water, a scarab ring, hundreds of inlay beads and gold foil used to decorate royal coffins.

“This is unprecedented,” archaeologist Zahi Hawass tells CNN’s Julie Zaugg and Nourhan Moustafa. “Up until now, everything we knew about the [Luxor region] came from the tombs themselves, but this new discovery will allow us to shed a light on the tools and techniques used to produce the royal coffins and the furniture placed in the tombs.”

The ministry also announced the discovery of a grave in the East Valley, or as it’s more commonly known, the Valley of the Kings. Per Ahram Online’s Nevine El-Aref, the tomb, called KV 65, boasts tools used during its construction.

Egypt is currently conducting the largest excavation of the valley since 1922, when Howard Carter stumbled upon Tutankhamun’s incredibly well-preserved tomb. Archaeologists are hoping to find still-undiscovered royal crypts, including the final resting places of Queen Nefertiti, Tut’s widow Ankhsenamun, Amenhotep I, Thutmose II and Ramses VIII.