While restoring an 18th century statue, Spanish historians found what appears to be a makeshift time capsule in an unlikely place—the buttocks of a statue.

The statue portrayed the image of Jesus Christ during the crucifixion and had been hanging in the church of St. Águeda in northern Spain. The centuries-old statue was starting to show cracks and was coming loose from its cross, explained Gemma Ramírez.

Ramírez is a preservationist with the Madrid-based group Da Vinci Restauro, which worked on keeping the statue in good condition. It was when they were lifting the statue onto a work table, said Ramírez, that they first noticed something was inside.

When they removed a section of the statue carved into the image of a cloth, Ramírez and her colleague discovered that the artwork's hollow bottom contained a document that details life in late 18th century Spain.

Two handwritten letters, yellow with age, were inside. They're dated from 1777 and signed by Joaquín Mínguez, a chaplain from the Burgo de Osma cathedral.

In his letters, Mínguez paints a picture of the region's day-to-day economic and cultural activity. The chaplain first notes that the statue was created by a man named Manuel Bal, who created other wooden likenesses for churches in the region. He then describes the successful harvests of various grains like wheat, rye, oats, and barley and stores of wine.

Mínguez also names diseases like typhoid fever plaguing the village during this time period, but adds that cards and balls were used for entertainment.

Outside of village life, Mínguez details Spain's political climate. He writes that King Carlos III is on the throne, and that the Spanish court is in Madrid. The letter even contains a mention of the deadly Spanish Inquisition, which lasted from 1478 to 1834.

The general and wide-ranging nature of Mínguez's letters mean he likely intended them to be a kind of time capsule for future generations, historian Efren Arroyo told Spanish newspaper El Mundo. Arroyo added that it's uncommon to find artifacts hidden inside church statues.

It's one of the most surprising discoveries made by the restoration group, they say. The Madrid-based team has previously worked on restoring old paintings, statues, and antique furniture.

The recovered letters were sent to the Archbishop of Burgos, where they will be archived. A copy was made and placed back into the buttocks to preserve Mínguez's intent.