MrTunnel.com  
   Discusses many projects.
   http://www.mrtunnel.com/

The Tunnel Page  
   The longest road and rail tunnels in the world, grouped by categories such as sub-sea tunnels and immersed tubes.
   http://home.no.net/lotsberg/

Bridge of the Month Quiz  
   An image is posted inviting entrants to identify the feature. A free copy of a book on the subject is awarded to one correct entrant per month.
   http://www.bridgeink.com/

The West Point Bridge Design Contest  
   Annual competition sponsored by the American Society of Civil Engineers. Includes free software download.
   http://bridgecontest.usma.edu/

Structurae: International Database and Gallery of Structures  
   Compilation of many features worldwide, including bridges and tunnels. Some entries include photographs.
   http://www.structurae.de/

The Bridges Project  
   Online database of significant bridges compiled by the Department of Civil Engineering at Rice University. Includes photographs.
   http://bridges.civil.rice.edu/

A Span For All Seasons  
   A collection of photographs of facilities and a large worldwide inventory of suspension bridges.
   http://www.bridgemeister.com/