Baltimore World Trade Center von I. M. Pei#39.286017,-76.6118467 (Baltimore is one of 16 charter members of the World Trade Centers Association) is the world's tallest regular pentagonal building. Just the pentagonal JPMorgan Chase Tower in Houston is taller, but this edifice is irregular. Planning and design of the building began in April 1966 by the architectural firm Pei Cobb Freed & Partners. Construction started in October 1973 and was completed in Janurary 1977. Its construction costs amounted to $22 million. The World Trade Center is 123.5 meters high and has 30 stories and includes a floor area of 422,000 sq ft. It is located beside The Inner Harbor.