· World Trade Center Memorial Competition
This site, sponsored by the Lower Manhattan Development Corporation, is a virtual exhibition that contains all 5,201 submissions for the memorial design. It is searchable by the designer's name, as well as country, state and entry number.

· The Port Authority of New York and New Jersey
The Port Authority's Web site has more information about Santiago Calatrava's transportation hub, including a Power Point presentation that shows the inside and outside of the building from many angles.

· Silverstein Properties
The Web site of Silverstein Properties, the leaseholder of the World Trade Center site, has more information about the office buildings to be reconstructed on the site.