Park51, originally named Cordoba House, is a planned 13-story Muslim community center to be located two blocks from the World Trade Center site in Lower Manhattan. The majority of the center will be open to the general public and its proponents have said the center will promote interfaith dialogue. It will contain a Muslim prayer space that has controversially been referred to as the "Ground Zero mosque", though numerous commentators noted that it was neither a mosque nor at Ground Zero. - Source: Wikipedia
