Amusement parks communicate with their visiters by using signs.
In order not to get lost in an amusement park, it is recommended to use signs to indicate attractions, menus, restaurants, toilets, entrances and exits...
Signs doesn't restrict to amusement parks, even schools, playgrounds or shops can use signboards, for cautionary or educational purposes.

Plopsaland Germany (HolidayPark)

Walibi Belgium

Click on the picture for a larger version.