Virginia Beach Maritime Historical Museum, Atlantic Wildfowl Heritage Museum, and the Virginia Aquarium and Maritime Science Center. A scenic overlook is located at the north end of the bridge and was formerly located at South Thimble Island, near the south end. At South Thimble Island, passing ships may include U.S. Navy warships, nuclear submarines, and aircraft carriers, as well as large cargo vessels and sailing ships. A restaurant and gift shop on the island opened in 1964, along with the Sea Gull Pier. Bluefish, trout, croaker, flounder, and other species have been caught from the pier. Since birds use the habitat created by the bridges and islands of the CBBT, birders have travelled to the bridge–tunnel to see them at South Thimble Island and the scenic overlook at the north end. As part of the Thimble Shoal Channel Tunnel twinning, the building housing the restaurant and gift shop closed and access to the pier was prohibited starting at the end of September 2017. The building will be demolished and not replaced, and the pier will reopen to the public at the end of the project in 2022. Dimensions Among the key features of the Chesapeake Bay Bridge–Tunnel are two tunnels beneath the Thimble Shoals and Chesapeake navigation channels and two pairs of side-by-side high-level bridges over two other navigation channels: North Channel Bridge ( clearance) and Fisherman Inlet Bridge ( clearance). The remaining portion comprises of low-level trestle, of causeway, and four man-made islands. The CBBT is long from shore to shore, crossing what is essentially an ocean strait. Including land-approach highways, the overall facility is long ( from toll plaza to toll plaza) and despite its length, there is a height difference of only from the south to north end of the bridge–tunnel. Man-made islands, each approximately in size, are located at each end of the two tunnels. Between North Channel and Fisherman Inlet, the facility crosses at grade over Fisherman Island, a barrier island that is part of the Eastern Shore of Virginia National Wildlife Refuge administered by the U.S. Fish and Wildlife Service. The columns that support the CBBT's trestles—called piles—would stretch for about if placed end-to-end, roughly the distance between New York City and Philadelphia. Incidents The CBBT has been closed three times for multiple days after being struck by watercraft: In December 1967, coal barge Mohawk broke anchor and struck the bridge, closing it for