Monticello, the former plantation overseen by America’s contentious third president Thomas Jefferson, remains the country’s only private residence deemed a UNESCO World Heritage Site. Nevertheless, the renowned property, which nearly fell into ruin shortly after Jefferson’s death, still holds secrets. In 2025 alone, archaeologists there unearthed unusual creamware, and evidence that Monticello had prototypical bathrooms. Now, experts have uncovered yet another striking find—a 250-year-old kiln where enslaved people and indentured laborers fired the bricks used to build Monticello.

This latest discovery first turned up in 2018 on Monticello’s East Lawn, mere feet from the home, as part of the Plantation Archaeological Survey, which has mapped the estate’s archaeological sites since 1997.

Researchers returned to conduct more extensive excavations earlier this month ahead of a planned upgrade to a nearby bus boarding area. “In our first few quadrants, we uncovered a continuous layer of brick rubble,” academics associated with the find wrote. The crew kept digging, and uncovered two uniform segments of bricks, each two bricks wide.

S-shaped specialty bricks from Monticello East Lawn brick kiln excavations. Photo: Miranda Leclerc, courtesy of Monticello.

At first, they thought they’d found a pile of bricks brought up to Monticello’s main mountaintop house from the property’s previously identified kilns. These were situated near the base of the estate’s namesake, where a stream provided necessary water. But, further excavations at the East Lawn site yielded three additional uniform and parallel segments—with burn evidence in between.

Soon enough, archaeologists realized they’d discovered another disassembled kiln. Their next challenge? Dating it. Several standout bricks unearthed here offered critical clues. Three embossed, cyma-shaped bricks and another specimen featuring ovolo-shaped molding indeed indicated that the kiln dates back to Monticello I—the first iteration of Jefferson’s home, which laborers built between 1768 and 1782.

Manager of Archaeological Field Research Crystal O’Connor points out the water table bricks on the dining room wall of the Monticello mansion. Photo: Crystal O’Connor and Fraser Neiman, courtesy of Monticello.

Those builders would have used such bricks to craft Monticello I’s neoclassical water tables. These stylistic features, stationed where the building meets the ground, divert water from weakening a structure’s foundation. The curved bricks used to build them conclusively date the new kiln to Monticello I because the home’s subsequent iteration, Monticello II, renovated between 1796 and 1806, didn’t include any water tables. Jefferson based Monticello II on the buildings he admired while serving as U.S. Minister to France between 1785 and 1789. By that time, water tables had gone out of style.

The discovery of this mountaintop kiln answers questions raised amid last year’s preparations for new accessible pathways on the mountaintop. There, archaeologists stumbled upon a heap of brick rubble along the East Lawn’s south edge. “Initially, we thought the rubble might be debris from the demolition of Monticello I,” the team explained. Alas, they didn’t find the expected mortar. Now that it’s been correctly identified, though, this newfound kiln offers a fuller account of how construction at Monticello evolved.