The Arch is a replica of the Arc de Triomphe in Paris. It has an eternal flame, lit by Nkrumah himself. The Independence Square is a big parade ground at the seaside with space for 30.000 people. There is also a huge stadium. All this is built by Nkrumah in the sixties.
When I visited Accra in December 2003, I was surprised by the traffic at this square, so much more than the first times I visited Accra. At the parade and stadion grounds was a large meeting of the Presbyterian Church. This wasn't difficult to find out because most women were wearing African dresses, showing the purpose of the meeting that day.

