All of the images are underexposed and your composition is lacking in the first two.
1. As per your title, the tunnel is the subject of the photo, but its almost out of the frame so what I'm drawn to look at is all the grass on the right. I'd zoom in closer to the tunnel and crop out a lot of the dead space at the top and right.
2. This really lacks a point of interest. If there were something special about the pole, it might work, but its just a pole on an empty beach....:thumbdown:
3. With just a bit more lighting, this would be a very nice shot. I like how the sunlight is coming through the doors. :thumbup:
4.The exposure on this isn't bad and the shot is a really nice abstract. :thumbup:
Well that was a waste of time ---just realized someone opened a post made back in the middle of May! Sheesh! OP has probably long forgotten this thread by now. Oh well.....