A nearly 200-year-old mansion in Chadds Ford that is known as the "Rocky Hill Castle" was gutted in an overnight fire.

Crews were called to the estate at 119 Bullock Road shortly before 2 a.m. Tuesday.

Firefighters encountered heavy flames at the stone mansion, which was built in 1821 and up for sale.

The extent of the damage wasn't immediately known, but was significant.

The cause of the blaze remains under investigation.

No injuries were reported, police said.

The current owners bought the property in 1957, according to real estate listings.

The 12-bedroom, 3.5-bath, 8,496-square-foot home was listed at $674,000.

The listing says the residence was originally a summer home for a Philadelphia business owner. During major renovations in 1912, the original Victorian-style home with a wraparound deck was converted into the existing stone "castle."

The home and a barn on the property both needed extensive renovations, the listing said.