Photo courtesy Port Authority of NJ/NJ

Opening to traffic for the first time in 1937, the Lincoln Tunnel connecting Weehawken, New Jersey to Midtown Manhattan was hailed as the next great engineering triumph of the decade. The New Deal’s Public Works Administration provided funds for its construction in 1934, fresh off the success of the southern Holland Tunnel, the first mechanically ventilated underwater automobile tunnel to be built under the Hudson River. A second tube was built shortly after the Lincoln Tunnel’s first, with a third built in the late 1950s due to increased traffic. To this day, the three tunnels service hundreds of thousands of cars and buses coming in and out of New York City. Here are the top 10 secrets of the Lincoln Tunnel!

1. Elephants Once Crossed the Tunnel on Foot

Elephants going through another New York City tunnel, the Midtown Tunnel

On May 17, 1971, a rail workers strike stranded a number of circus performers and animals from The Greatest Show on Earth about 5 miles away from Madison Square Garden, where they were set to perform that night. While most of the caravans made the rest of the journey by truck, a convoy of 19 elephants, a zebra, a llama, and a pony crossed into New York through the Lincoln Tunnel. No word on how, when they reached the other side, the handlers were able to get the animals eight blocks down 8th avenue to the Garden on 34th Street.