Here's a few of mine:
Crater Lake (Oregon, USA) Freaking amazing volcanic caldera lake that's like 2000ft deep, 6 miles across
Giant Redwoods (in Oregon/California USA) 300 foot trees, you feel very small walking among them
Grand Canyon (Arizona, USA) more than a mile deep in some places, and miles across.
Rocky Mountains (Utah/Colorado, USA) BIG mountains, see them from far away, then go in among them
Scottish Highlands (Scotland, UK) Stark bare mountains, many colors, especially cool if it's misty/raining.
Going to see Yosemite National Park and Sequoia National Park this year, so will have more to add
I tend to be much more 'wowed' by natural things, manmade things just don't do it for me.