In Populous, wherever there is no water, there is land. Land can differ on height and comes in sharp or smooth ways. What makes Populous and its levels so unique is the land-water interface, which will change in every single leve. Landscapes can also be different one from another: in early stages of the singleplayer campaign, the landscape is usually dirty or grassy, and as you get closer to the sun, it will get drier. There are other landscape types like snowy or mitstic, and some tools allow you to create your own landscapes.

Units can only walk on land, like most objects in the game. Balloons will travel above it, but boats can not travel through land - if a boat is sent to land, it will become useless and explode after some seconds.

If lava interacts with water, it will create damaged land, which will later become fertile.

You can also only build on land, and only on smooth areas enough for the building plan to fit.

The land modifyer spells are the landbridge, flatten and erode - but other spells can modify land, such as volcano, earthquake or the forge world spells (only avaliable online).

It is possible to sink a reincarnation site (but the pillars will not drown) - but once the shaman reincarnates, land will rise and she will not sink.