. "-4" . "-5" . "804" . . "2.1336"^^ . . "23064" . . "Grimstead is an unincorporated community in Mathews County, Virginia, United States. Grimstead is located on Gwynn's Island 4.5 miles (7.2 km) north-northeast of Mathews. Grimstead has a post office with ZIP code 23064."@en . . . "Grimstead, Virginia"@en . .