Hi Claudio,
How many photos do you want to have in that gallery? I think you have a little more than 50, and that might make a good book. Why not just keep it where it is? I guess if you wanted to make a collection of posters or prints for a gallery showing, you would want to go through that gallery and try to pick your one or two favorites. Then in your first selection you would have 5 or 6 or maybe as many as ten or a dozen favorites to choose from. You could make a collection of prints from those. The first one stands out in my memory. So does the one with the green and white in patterns. I can't think of another one that stand out in my memory right now. I'll go take another look.
O.K. Now I was just starting to look again, and I found number 4 to be very interesting. I also like number 6, because of the little people along the ridge. That photo begs to be printed large (maybe 20" x 40" or a little over a meter across). Looking through the others I found number 24 to be pleasing, and the cracked up "wall" in number 28 is interesting.
I think number 30 makes a really nice landscape shot (though I do realize these are pretty much all landscape shots). Number 31 is almost an abstract image, because of the different parts. It almost doesn't seem real, so that's an interesting shot too. I like the crazy rock formations in number 42, and the ice on the rocks in number 56 really stands out.
I think number 40 is probably my favorite, though a favorite is difficult. I like forest scenes, so maybe it's the green grass that attracts me to number 40, but it might be the variations of color and the "pattern" of the land. The brown in the top right of that photo bothers me though, so I think if it were my shot, before making a large print of it, I would experiment with cropping it to various formats. I tried cropping it to a 1:2 format, eliminating some of the right and a little from the top of the photo, and I liked what I got.
Good luck with your selections Claudio.