Frogmore Plantation Complex, Historic plantation complex on Saint Helena Island, South Carolina, United States

Frogmore Plantation Complex is a historic site comprising a main residence, pump station, barn, and windmill tower scattered across coastal South Carolina land. The structures date from different periods and show how the property developed over time.

The property was established in the mid-1700s and the main house was built around 1810, later expanded in the late 1800s. Following slavery's end, the site was repurposed as an educational institution.

After the Civil War, northern missionaries Laura Matilda Towne and Ellen Murray bought the house and founded the Penn School, held within the Penn Center. The school taught newly freed enslaved people of St. Helena Island, and the Penn Center remains a cultural and educational centre for the Gullah Geechee.

The complex lies on Saint Helena Island in Beaufort County, South Carolina, and is reached by secondary roads off the routes serving the island. The plantation home, pump house, barn and windmill/water tower stand apart from one another, so allow time to walk between them.

The barn features tabby construction, a regional technique that combines oyster shells, lime, sand, and water into durable structures. This building method reflects practical innovation using materials readily available in the coastal area.