Biggest all-wood structure in the world....used to test electro-magnetic pulse from nuke weapons. At Kirtland AFB, NM (ABQ airport). Pretty damn cool to see, and even cooler that it supported the weight of a B-52 parked on top.
http://www.brook.edu/FP/projects/nucwcost/trestle.htm http://www.bhinc.com/groups/bh/featu...le/trestle.cfm