If you're looking for hills, they are usually quite easy to spot.
They appear as big lumps in the ground. They are often disguised with a covering of trees, fields, planned urban developments and stuff like roads and bridges. You rarely see lakes on the slopes of a hill. You see rivers, but they often contain fast-moving water.
If you are cycling when you encounter one, you will find it easier to maintain progress if you tap the brake levers with the thumb (left hand) and the fingers (right hand). I do not know the reason why, but this usually works... although it seems not to on my fixie.
Contrariwise, on the other side of hills, the reverse action with your digits will allow progress at quite unseemly speeds and you will feel like Fabio Cancellation or Marco Panini. You are allowed to say "Weeeee!" on the other side of a hill, but not on the first side you get to, where it would just sound silly.
I hope you have fun looking for the hills you're after and hope my suggestions work for you if you find any.
It is my wish to be helpful, although I fear I do not always succeed.