Final answer:
The Chesapeake Bay Bridge-Tunnel is an 18 mile-long engineering marvel located in Virginia, connecting Cape Charles and Norfolk and providing a significant transportation route.
Step-by-step explanation:
The state with the 18 mile-long Chesapeake Bay Bridge-tunnel spanning the mouth of Chesapeake Bay, connecting Cape Charles with Norfolk, is Virginia.
This engineering marvel is an important transportation link that not only serves as a vital route for residents and travelers but also reflects significant advancements in civil engineering and transport infrastructure.
The Chesapeake Bay Bridge-Tunnel allows for direct travel between the Delmarva Peninsula and Southeastern Virginia, bypassing the around 95-mile trip around the bay through the Baltimore-Washington metropolitan area, thus significantly reducing travel time between these regions.