Abandoned Military Tunnel at Hawk's Hill
This tunnel is one of several in an abandoned military structure at Hawk’s Hill in the Marin Headlands just above the Golden Gate Bridge. The structure was built to defend San Francisco from an attack by sea during World War II but was abandoned before completion near the end of the war when it was apparent America was not at threat.
I shot this out through the sunroof of my car while driving across the bay bridge into San Francisco yesterday evening, so it is really just a lucky shot. I liked how the perspective turned out, considering it was completely random (I literally just stuck the camera out through the roof, took basic aim and clicked the shutter button).
And by the way, for anyone that might be concerned, traffic was crawling across the bridge at a snail’s pace… so I didn’t risk my life or anyone else’s taking this shot! 
Here’s another interesting architectural shot, similar to the photo from the Westfield Shopping Centre. This time it’s a photo of the Space Needle in Seattle, Washington from a trip I took there earlier this spring. The lower part of the needle has a lot of glass, making for nice reflections. I took this looking straight up near the entrance of the building, just before sunset.
Here are a few more photos of the space needle I took on the same day:
I happened to pass through the Westfield Shopping Centre in San Francisco on Saturday and took this photo looking up at the many levels of the mall from the bottom floor. Not the most interesting subject, however I liked the perspective and the architecture composition of the photo.