In India too, the floor at the ground level is called the ground floor (probably that is where the name came from), the one above it is called the first floor, and so on. The convention is probably from British colonial times.

Also LED floor numbers in lifts (elevators) in India start from 0 for the ground floor, as do the buttons that you press to go to specific floors.

Also, Ground Zero.

https://en.m.wikipedia.org/wiki/World_Trade_Center_site

https://en.m.wikipedia.org/wiki/Hypocenter#