Well done, Andrew!

Very nice composition in all three and you can see what a difference it makes can't you.
I think in the first shot, for a supposeldy spooky ruin, it doesn't look particularly spooky. Take a look at today's POTD and see how they've managed to create some atmosphere in their final image by boosting the colour curves and creating areas of light and dark. I think your black and white conversion could do with the same, plus a bit of motion blur/wind blur in the clouds might look good too.
Your shot of the bridge has that "I captured it like this in camera" look to it, but again it's well composed. You could really got to town with the editing and create some atmosphere with it too if you fancy a challenge. Again, have a look at the POTD for inspiration.