6. Chesapeake Bay Bridge and Tunnel

Named one of the seven engineering wonders of the modern age, the Chesapeake Bay Bridge and Tunnel connects Virginia proper with its easternmost landmass. Stretching 17 miles across the historic Chesapeake Bay, the structure represents a man-made boundary between the Bay and the Atlantic. The structure includes two 2-lane highways supported mostly by trestles, four man-made and one natural island, two truss bridges, and two revolutionary sunken tube tunnels.