At Natural Bridge, Virginia.
Formed millions of years ago by the collapse of a massive cave due to water erosion of what is a seemingly benign little creek, Natural Bridge is a great natural attraction and National Historic Landmark a couple hours’ drive outside of Washington DC. You can get a sense of how tall this structure is (20 stories tall!) by comparing the height of the trees along the top (which has a paved road used by normal traffic–yes you can drive across this and probably not really know what’s beneath) or better yet, by comparing the height of the tourists at the bottom of the shot. A beautiful sight along a trail to a cool little waterfall as well.
Nature never fails to impress.