a lens not to be under-estimated in it's own right (assuming the first version with the metal mount)
First two are great! I love the exposure differential between foreground and bacground in the first, and the composition of the second. The last is a dramatic perspective, but I must admit that I have never seen a fisheye image that I wouldn't have preferred to have seen taken with an UWA lens, even if the coverage is less minus the fish effect.
With adapted lenses I found that it was good to mess around with them if you already had them or could find them cheaply, but I could never seriously build a system around adapted lenses. They're still fun to use, but the native m4/3 lenses do it so much better.
I like the way the Coins and Cards booth pops relative to the Cathedral in the background. I thought it was a post-processing effect.
As to the bottom shot, obviously the catherdral builders were sampling some of the grapes that grew during the Medieval Warm Period -- the building is bent!