One can see the light at the far end of the tunnel with this underground tunnel in Fort Worden State Park.
"Fort Worden, along with the heavy batteries of Fort Flagler and Fort Casey, once guarded nautical entrance to Puget Sound. These posts, established in the late 1890s, became the first line of a fortification system designed to prevent a hostile fleet from reaching such targets as the Bremerton Naval Yard and the cities of Seattle, Tacoma and Everett. Construction began in 1897 and continued in one form or another until the fort was closed in 1953. The property was purchased as a state park in 1955. Fort Worden is named after Rear Admiral John L. Worden."