Sandbox Mode
Sandbox Mode is a free-form building mode available in RollerCoaster Tycoon 3, which allows players to build nearly anything. There is unlimited money, no objectives, and a large 128 x 128 plot to build on.
In sandbox mode, all rides, scenery, and other attractions are unlocked from the beginning, which allows players to create parks of any design and any theme.
Many think Sandbox mode is also more fun than Career mode because it's not about the money,instead its about more ride popularity and also gives you more freedom to mess around and set your own goals. Also in Career mode you start off with a few rides whereas in Sandbox you start with nothing so the park can be completely your own.