Creator Alex Hirsch says Gravity Falls was inspired by the cheesy tourist attractions around Oregon, USA, including a local town called Boring
The number 618 comes up a lot and is actually the birthday of creator Alex Hirsch and his twin sister Ariel. They were the inspiration for Dipper and Mabel.
Lots of the hidden messages can then be solved by swapping out different letters in the alphabet. Messages include 'whatevs', 'happy now, Ariel?' and to 'game is over and I won'.
Dipper gets his nickname from a birthmark but his real name is still a mystery. One writer has joked that it’s Llominic, like the name Dominic meets Llama. But in one episode he’s referred to as Roderick.
At the end of each episode there's a wheel with 10 images around the edge. 8 of these are about different characters in the show but there's also a picture of an open bag of ice and a llama, which no one is sure what they mean!