Inwood is a census-designated place (CDP) in Berkeley County, West Virginia, United States, located south of Martinsburg. The population was 2,954 at the 2010 census. It is located on U.S. Route 11. In the late 1880s, coinciding with the arrival of the Cumberland Valley Railroad (CVRR) extension, a resort that became known as Inwood Park was established on the property of the Strong family of south Berkeley County, West Virginia. On May 5, 1890, the Inwood Post Office opened and the village grew around the Park. From 1892 - 1913, an annual event called the Inwood Fair was held at the Park. This event drew in the range of 7,000 - 12,000 people.