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Terraria map size, biomes, and how they work

If you think the Terraria map is a straight line, then think again - the expanse has diverse biomes, multiple subterranean variants, and areas that can corrupt.

The Terraria map is sunny with blue skies and a green field

How big is the Terraria map? It’s a complicated landscape comprised of randomly generated space. Unique characteristics separate the lot, from the terrain and its residents to the valuable loot you can find nestled within. With it changing over time as you defeat powerful enemies, it only gets harder to understand as you progress deeper into its dank caverns and twisting tunnels.

Whether you want to learn more about the Terraria map in your first play session or your 50th, there’s always more to read up about. We won’t go into every tiny detail about each of the Terraria biomes to keep things simple and easy to und. Still, you’ll want to load up the Terraria bosses guide and the Terraria happiness guide to add a bit of additional context. And if you want to spice it up for another run, the best Terraria mods are considering.

The menu shows the Terraria map size

How big is the Terraria map?

The size of a Terraria map depends entirely on the setting you choose while generating it. You have three options, with your selection affecting the size of the created world in terms of the following tile sizes:

  • Small – 4200 x 1200
  • Medium – 6400 x 1800
  • Large – 8400 x 2400

Is the Terraria map randomly generated?

Yes, just like the voxel mainstay it’s primarily inspired by, the Terraria map is generated entirely at random. Once you click to create a new world, it’s all built from scratch using a certain set of rules.

With enough searching, you’ll always find the same biomes, but they’ll never be in the same place or share the same layout as another world. Your goals will largely remain the same, but how you achieve them will differ slightly because of this.

The Terraria map is made up of different biomes

What are Terraria biomes?

The Terraria map is made up of “biomes” – distinct areas characterized by unique terrain, enemies, items, and more. By understanding what each biome offers, how they look, and the purpose they serve, you’ll be in a better position to search for them and understand how best to navigate them.

Certain materials can only be collected in specific biomes, and particular bosses can only be triggered and summoned by completed sub-tasks in their corresponding areas. Without understanding Terraria map biomes, you’ll struggle to complete the game.

All Terraria map biomes

The Terraria map can be split into two distinct categories: surface and underground biomes. As the naming would suggest, surface biomes appear at ground level with the sky visible above, whereas you unearth underground biomes the further down you dig. An underground biome type cannot generate on the surface, nor vice versa.

The Terraria map has surface biomes including ice

Surface biomes

Glowing Mushroom

  • You can foster this man-made biome by planting Mushroom Grass Seeds. Eventually, it will grow into a great place to harvest particular items and craftable equipment.


  • Coded to appear on the opposite side of the Jungle biome relative to your initial spawn point, the Dungeon stands out with its blocky entrance and mysterious Old Man. It runs all the way down to the Underworld, featuring unique rewards, powerful items, and the means to summon the Skeletron boss.


  • Easily identified as a large body of water, the Ocean biome can serve as a great fishing spot, a spawn point for the Duke Fishron boss, or a place to farm some enemies unique to its depths.


  • The vast Jungle biome is easily noted by its dense vegetation and tree-laden backdrop. Great for gathering wood and other natural materials, it’s reliably found on the same side as the Desert.


  • One of the two possible evil biomes, the Corruption runs mostly straight down, with Demon Altars and Shadow Orbs being exclusive to it. It plays a key part in progressing into Hardmode.


  • One of the two possible evil biomes, the Crimson zigzags through the terrain beneath, with Crimson hearts and Crimson altars not only offering powerful equipment when broken but necessary for summoning a boss required for the Hardmode unlock.


  • Always found on the opposite side of the much hotter Jungle biome, the snow biome typically serves to signal the Ice biome’s proximity beneath.


  • Often the place of many early scuffles, the Desert biome isn’t always limited to just one, though there’s no guarantee a second will spawn another instance of its underground equivalent.


  • Featuring more colorful flowers and smaller trees than the green-coated Jungle biome, the Forest biome is the most common Terraria map location and often the spawn point of choice.

The Terraria map has underground biomes

Underground biomes

These biomes largely mirror their surface counterparts, which they’re situated beneath.

Because of their tunnel-life construction, navigating underground biomes is typically far more dangerous than their above-ground versions. Unique enemies often trap people in small spaces.


  • The subterranean equivalent of the snow biome Features Thin Ice coating its underground water reserves. It is generally easier to traverse, and ice-themed items are common in the chests you’ll encounter.

Underground Desert

  • Located beneath the Desert biome above ground, its caverns can spawn various agile enemies. The biome is mostly made up of Sandstone Blocks and Hardened Sand Blocks. Should this area suffer the effects of Corruption, Crimson, or Hallow because some sand touches an infected area, it will strengthen enemies, including the appearance of Desert Spirits. Removing the background wall will remove the biome’s effects.

Underground Jungle

  • Playing host to the Queen Bee in easy mode and two bosses during Hardmode, this Underground Jungle is an extension of the Surface Jungle, being easily found by digging from one to the other. It’s full of treasure rooms, but also many tough enemies. In Hardmode, it can become corrupted by the Evil Biome, spawning Chlorophyte Ore and Life Fruit.

Underground Mushroom

  • If you’re after Truffle Worms in order to summon Duke Fishron, this is the best place to farm them. Characterized by its signature glowing mushrooms, you’ll know when you come across this area. You’ll need to harvest mushroom-related tiles here to create the Surface Glowing Mushroom biome.


  • Always situated at the very bottom of the map, this biome stretches across the whole y-axis. It features deadly lava, ruined houses, and the spawn point for the Hardmode-triggering Wall of Flesh boss. Come here to collect Hellstone.

A house is built in a Terraria map biome

Is the Terraria map different in Hardmode?

As soon as Hardmode is triggered by defeating the Wall of Flesh boss, the Terraria map will begin to change slowly. This is due to the introduction of new biomes specific to the hard mode experience and the bosses they serve to enable. Both the Surface and Underground will be altered to feature these new biomes.

Hardmode biomes like Corrupted, Hallowed, and Crimson will spawn in place of previous surface-level Desert biomes, and their altered sand blocks will slowly spread into a nearby ice biome as well.

Need a break from all that knowledge? Get some insight into the game’s development with the anecdote on the Terraria creator’s favorite boss, the new items that stemmed from a Terraria forum war truce, and the Terraria collaboration the creator wants the most.