Human beings are used to being on the ground, standing right side up. So when you view the world from a different perspective, such as from aerial photographs, things often don't look quite right. Minute Physics explains a common optical illusion used to make maps easier to read:
Thanks to Skillshare for supporting this video: http://skl.sh/MinutePhysics for 2 free months! This video is about a multistable perceptual illusion, similar to the hollow face illusion, whereby maps or aerial or satellite photos look upside down/inside out, ie, concave (valley) parts look convex and convex (mountainous) parts look concave.