Ingress, an older game by Niantic.
Depending of how the people played ingress in your area, there will be more/better landmarks or just shit.
The quantity of pokemon in an area is counted by the triangulation of pokestops, you can see this triangualtions in the ingress app.
My area was full of communists and wannabe artists playing ingress it seems, so the majority of pokestops are shitty political messages and graffitis (even some landmarks are not counted, prefering to use a shitty graffiti that is not even there anymore just 100 steps aways form it). Theres even a gym that is called "Girl with penis" and has, of course, a garffiti of a girl with a penis. Dont know how much time is going to pass with that until nintendo decides to take that gym away.
They also triangulated the thing like shit so the area has very few pokemons.