I think the fundamental reason why people appreciate visiting places with beautiful landscapes is that it is restful to the mind, body, and spirit to look at the beauty, especially that which is found in nature. Being in the great outdoors helps us reconnect with our roots and our most basic selves. This is a useful reminder that we, as humans, are not apart from the natural world that sustains us. This might be a return to our caveman ways. Simply said, humans are creatures, just like every other creature. Mankind has put forth a lot of effort in several areas to separate itself even more from nature. Breathing fresh air apart from all the man-made steel, concrete, and plastic is a nice break.