Currently the seat of the Ghanaian presidency, Osu Castle is one of Accra's most well-known historical sites. Built as a slave fort by the Dutch in the 1660s, Osu Castle was later occupied by the Portuguese, British and finally Ghana as an independent nation. While the castle is not open to the public, it can be viewed easily from Independence Square. Take note of its unorthodox shape, a result of numerous occupiers, renovations and additions over the years. Independence Square is an important historical site in its own right. It contains the Independence Arch, Black Star Square and the Liberation Day Monument, all with their own tributes to freedom and justice. Commemorated upon Ghana's independence, this square has remained an important gathering space for Ghanaian citizens.