You can download "Minecraft" maps that others have made and play on them yourself. "Minecraft" maps can be downloaded for free from community sites like Minecraft ...

Though Minecraft's world map is massive, it does not take up a lot of space on a device. The game's worlds are essentially only the information of the seed and what has been tweaked by the player.

NOTE: Yes, I require you to have quite a bit of technical knowledge when it comes to Java and other things such as that. As well as folder locations, unzipping, how jars/modding works in Minecraft, ...