Robertsport, also known as Roberts Port and Robert's Port, is a town in western Liberia, about 10 miles from the Sierra Leone border. It is named after Joseph Jenkins Roberts, the first president of Liberia. The town lies on Cape Mount peninsula, and is separated from the mainland by Lake Piso. It serves as the capital of Grand Cape Mount County. Robertsport is located 50 km north of Monrovia, Liberia's capital city. As of the 2008 census, Robertsport has a population of 3,933. Of this, 1,994 were male and 1,939 female. The town gets very heavy rainfall, averaging 205 inches (5,200 mm) per year.