The city has several notable cultural attractions. The Victoria & Alfred Waterfront, built on top of part of the docks of the Port of Cape Town, is the city's most visited tourist attraction. It is also one of the city's most popular shopping venues, with several hundred shops and the Two Oceans Aquarium. The V&A also hosts the Nelson Mandela Gateway, through which ferries depart for Robben Island. It is possible to take a ferry from the V&A to Hout Bay, Simon's Town and the Cape fur seal colonies on Seal and Duiker Islands. Several companies offer tours of the Cape Flats, a mostly Coloured township, and Khayelitsha, a mostly black township.