The Monrovia metropolitan area, including the downtown area, nearby districts, and suburbs, has an area of approximately 13 square kilometers (five square miles). The downtown grid is home to government buildings, including the Capitol, Executive Mansion, City Hall, and Temple of Justice; foreign embassies; the Waterside Market; the National Museum; and hotels. Diminutive Providence Island, north of the city center, is the spot where the first freed slaves from America arrived in Liberia in 1822. To the east lie Bushrod, Bally, and Bank Islands. Bushrod Island, where the Free Port of Monrovia is located, is the city's industrial center and the location of its deepwater port. Sinkor, southward along the Atlantic coast, is Monrovia's major suburb and is also laid out in a grid pattern, with numbered streets and named avenues. Yet further south are the older district of Congotown, the Spriggs-Payne Airfield, and the Robertsfield Airport. Shantytowns with corrugated iron and cardboard houses extend along the edges of the city.