Archaeologists recently announced the discovery of a 14th century castle – complete with a moat – under a hotel in Vannes, France.

The castle, which has been identified as the Château de l'Hermine, was built by John IV the Conqueror in the 1380s. It is located under the courtyard of Hotel Lagorce.

In a Mar. 26 press release translated from French, the National Institute for Preventive Archaeological Research (INRAP) explained that the excavations were carried out between the spring and autumn of 2023. Archaeologists were shocked by how relatively complete and well-preserved the castle's remains were.

"The excavation revealed little by little the plan of the ground floor: the ducal house, 42 meters long and 17 meters wide (out of work), is endowed with walls of an  exceptional thickness," INRAP explained. A ducal house refers to a house inhabited by a duke, which John IV was.

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"Directly bordered by a moat, it is flanked to the west of what  one can call a ‘square tower.’"

Researchers also discovered "several" staircases, one of which was "a remarkably preserved staircase, with a decorated core and three steps."

In addition, excavators found dozens of objects "related to the daily life of the castle," including coins, cooking dishes and jewelry.

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The humidity of the area also preserved remarkable wooden items, including fragments of barrels.

"In addition, archaeologists conducted a deep survey in the moat," INRAP explained. "From this very wet material, they extracted rich furniture."

Archaeologists even found tiles covered with graffiti, padlocks for furniture and pieces of clothing.

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INRAP also said that the site was incredibly well-managed.

"The homogeneity of the materials used for the construction of the castle and the standardization of the modules show a mastery of the management of the site throughout the operating chain, from the extraction of stone to its implementation," the INRAP release explained.

"The construction… took place in a single phase, which testifies to the importance of the financial and human resources used," the statement added. "The remains indicate that John IV knew how to surround himself with the best engineers and craftsmen of their time."

Fox News Digital reached out to INRAP for comment.