Many things, both great and (very) small.
A total solar eclipse (Straatsburg, 1990 or so).
Rain (and the ensuiing bloom) in the Arizonian desert.
The Milky Way, that one time I was on an island so far away from city lightning so I could see her for the first time. The times I saw falling stars in August.
The Grand Canyon, although it was rather too great to fathom; I kept on feelign I was watching a movie of the Grand Canyon all the time I was there. I enjoyed the ground squirrels hopping over my feet more.
Lots and lots of beautiful landscapes, seen on holidays in my own Netherlands. France, Belgium, Sweden,
The pinewoods of Spain near Sevilla, that looked like a park.
The wild orchids of mid-Italy, each aping another insect, and the Italian fields laying bare, covered with wild pink lilies…
Landscape parks and gardens in England.
The Dover coast in England, with the white chalk cliffs, filled with ammonite fossiles, and the pools during the low tide that were filled with strange cute sea anemones, scenty seaweed, hermite crabs and what I think were manganese nodules, silvery clumps of metal that came rolling from the seabed.
The time I lay on my belly on the Dutch Vlieland beach, looking at a muddy flat where all sorts of tidal plants grew and critters scurried around, and I imagined what a strange vegetation all that would be if I was smaller or they larger.
The way the world of vegetation just expanded with every new plant species I learned to distinguish. How much richer and more detailed and more meaningful the world became.
Friendly contact with animals:
The first time I discovered all the little critters in the garden pond and watched them for hours in fascination.
My cats. All friendly cats I met.
The time I wandered into the forest with a friend, sat down to talk, and after fifteen minutes or so, a wild boar, apparently tired of waiting untill we’d leave, but not afraid of us either, crossed the road, no hurry, on it’s dainty hoofs, occasionally looking at us as if to say “Please, carry on”.
The cows who came looking what I was up to if I sat quietly in what I thought was a meadow inaccessible to them. Suddenly, there’s a warm wet wind and a very loud “HH-hrmpf” at your ear.
The time I sat down in another meadow (I mapped vegetation at the time and occasionally sat down to organize my notes) and I saw a deer walking cautiously in my direction, clearly curious. I froze and she passed me at less then five yards, looking at me, but she never bolted.