(https://www.nyip.edu/images/cms/photo-articles/why-go-wide-01.jpg)
For those who prefer the great outdoors over the tight confines of a studio, the ultra wide angle lens is the way to go. This is generally in the 10-20mm range. Be warned, these lenses are so incredibly wide, it's possible to accidentally include your feet in the photo. Used correctly, you can create spectacular landscapes with sweeping views and colorful foregrounds. To avoid including unwanted objects in the scene, check all four corners of your viewfinder before taking the photo.
(https://www.nyip.edu/photo-articles/archive/why-go-wide)
Source: https://www.nyip.edu/photo-articles/archive/why-go-wide