Construction was begun on the Brooklyn-Battery Tunnel in 1940. Initially, Robert Moses had pushed for a bridge in the same place, but those plans were scrapped by the Dept. of War citing both security concerns (the bridge would be close to Brooklyn's Navy Yard) and citizen's outcry to preserve the Battery, which was largely undeveloped at the time (an unstated reason was Moses' feud with President Roosevelt.) Instead of a bridge, a tunnel was built to connect the two boroughs. Four towers ventilate the two-mile-long strip of underground highway, refreshing air every 90-seconds.