Vernal Falls in Yosemite National Park, CA
The 16" x 24" ratio is an aspect ratio of 2:3 which is commonly used for standard photo and artwork prints.
This print could also be printed in the following sizes:
4" x 6"
8" x 12"
12" x 18"
16" x 24"
20" x 30"
24" x 36"
30" x 45"
40" x 60"