
Only in the surface layer will regular, Corruption/Crimson and Hallow grass naturally grow and spread (although grass can be planted with seeds, Staff of Regrowth, or Axe of Regrowth in other layers, it will not spread). A surface Glowing Mushroom biome can be seeded here by players, but will never occur naturally. This layer also usually contains the world's Floating Islands, although these are generally located some distance above the main land mass. The entrance to the Dungeon is also found here. Meteorite biomes will usually be found here when they generate. The surface includes the Forests, Deserts, Corruption, Crimson, Jungle, Snow, Hallow, and Ocean biomes.

Harpies spawn here, and in Hardmode, Wyverns and Arch Wyverns. Gravity is reduced in Space, making characters jump higher and fall more slowly. The Sun, Moon, and stars are visible here against a backdrop that is always black, regardless of the time of day.

It generally contains no natural structures, although Floating Islands and Living Trees may occasionally extend into it. The range of numbers depends on platform, world size, and the randomized world generation of each world. Each reading includes a layer name: Space, Surface, Level Surface, Underground, Caverns, and Underworld. The Depth Meter numbers feet or meters above Level Surface, then feet or meters below Level Surface.

