The longest of its kind in the world is the Chesapeake Bay Bridge-Tunnel in Virginia

Chesapeake Bay Bridge-TunnelPhoto byFamartin/Wikipedia Screenshot

According to Only In Your State, Virginia's Chesapeake Bay Bridge-Tunnel is the longest bridge-tunnel complex in the world.

Virginia's Chesapeake Bay Bridge-Tunnel

According to Wikipedia:

"The Chesapeake Bay Bridge–Tunnel (CBBT, officially the Lucius J. Kellam Jr. Bridge–Tunnel) is a 17.6-mile bridge–tunnel that crosses the mouth of the Chesapeake Bay between Delmarva and Hampton Roads in the U.S. state of Virginia. It opened in 1964, replacing ferries that had operated since the 1930s."

The tunnel goes both over and under the open seas. It connects Delmarva and Hampton Roads.

Not easy to build

Building the structure was not easy, but it was a marvelous feat of engineering. The website states that building the complex meant "undertaking a project of more than 12 miles of low-level trestle, two 1-mile tunnels, two bridges, almost 2 miles of causeway, four manmade islands and 5-1/2 miles of approach roads, totaling 23 miles." The water varies from 25 feet to 100 feet deep along the route.