Tabby concrete is a type of building material that originated in the southeastern United States, particularly in coastal areas. It is made from a mixture of lime, sand, water, and crushed oyster shells, which are abundant in these regions. The use of oyster shells not only provides a unique texture but also enhances the material's durability. This concrete was commonly used in the construction of homes and other structures during the 18th and 19th centuries. Its natural ingredients make it an environmentally friendly option, and it is often associated with historical architecture in areas like Savannah and Charleston.