Cairo, Egypt. Despite crowd estimates of over two million people, El Tahrir Square and the adjoining access roads could only hold approximately 240,000 people at "mob" density (1 person per 2.6 sq ft).
This graphic shows the area needed for 236,000 people standing in formation with a density of 2.6 sq ft per person. 204,500 would fit in the highlighted area if the density dropped to 1 person per 3 ft and at a density of 1 person per 4 sq ft (still a dense crowd -arms length from on another) only 153, 400 would fit in the highlighted area.
This was definitely not a million man march. However it was still a very large crowd, just shy of the crowd size for the Rally to Restore Sanity and/or Fear on Washington, DC's National Mall.
