ATLAS-I Trestle

ATLAS-I is a decommissioned Cold War test facility built between 1972 and 1980 near Albuquerque, New Mexico, to harden US military aircraft against electromagnetic pulse effects from nuclear detonations. The wooden trestle structure — roughly 180 meters long, 65 meters wide, and up to 40 meters tall — remains to this day the world's largest metal-free wooden structure by enclosed volume. Metal was entirely excluded from the construction because even small ferrous elements would have distorted the electromagnetic waves generated by the facility's Marx generator, which was capable of instantaneous output up to 200 gigawatts. Now classified as historic ruins on Kirtland Air Force Base, the decaying trestle is barely accessible to the public, making it one of the more obscure and visually striking artifacts of American nuclear-era engineering.