Throughout its history, the opulent Forbidden City in Beijing has housed 24 Chinese emperors. Tourists can still visit the site today, but the location of an even older palace built in the area by Kublai Khan in the Yuan Dynasty has proven harder to pin down. Now the South China Morning Post reports that archeologists have uncovered remnants of the palace beneath the Forbidden City itself.

Archaeologists have long suspected that the Yuan palace had been located somewhere close to the Forbidden City, but they hadn't realized just how close until now. Experts from the Palace Museum announced yesterday that the foundations from the 13th century palace were discovered at the bottom of an archaeological excavation site at the Forbidden City's center.

The Palace Museum has been conducting digs in the Forbidden City since 2014 to learn more about its history. So far they've turned up layers of foundation from four dynasties–Qing, late Ming, early Ming, and now Yuan. Archeologists from the museum have also dug up a pit of discarded Ming Dynasty porcelain and the foundations from an early Ming Dynasty structure that had previously been unheard of.