The Skylands are a set of four season-themed biomes added by Terralith: Autumn, Spring, Summer and Winter. Each variant generates as a group of floating sky islands above deep ocean, with the islands at about Y 230 to 232. The four variants share the same island layout and differ in colours, trees, flowers and passive mobs.
All four variants carry the rare biome tag, and the mod's data gives each a surface share of 0.03% to 0.06% of land.
In Fear Nightfall the Skylands are not among the biomes given extra weight for the horror theme. Their monster spawns are the standard overworld set, and their main hazards are the height and the fall to the ocean rather than the mobs.
Autumn Skylands have golden grass (#dfd43d), orange foliage (#f5a821) and a blue water colour (#3f76e4). Their islands carry autumn-coloured trees and wheat patches, and the surface is covered with pumpkin and sugar cane patches. The biome's fog and sky colours are the same pale blue as the other variants.
Spring
Spring Skylands are the lightest of the four, with pale green grass (#9be6c0), pink foliage (#ffabcc) and a turquoise water colour (#43d5ee). The islands hold cherry and sakura-style birch trees, cherry-type flower patches and small lakes. Spring islands are the only variant with their own lake and flower features.
Summer
Summer Skylands have bright green grass (#89dd4e) and foliage (#b4ec4e), with the same turquoise water as spring. The islands carry acacia, azalea and vine trees, cactus, glowberry and tall-flower patches, and mud lines along the island undersides. Summer is the only variant tagged as hot (c:is_hot).
Winter
Winter Skylands are the coldest variant, with a temperature of 0.2 against 0.5 for the others. Their grass is a muted blue-grey (#6783af) and their foliage is grey-green (#879daf). The islands carry oak, big oak and mega spruce trees, and lichen grows on their surfaces.
Generation
The Skylands generate in the overworld under the same climate rules as the rest of Terralith, with a downfall of 0.5 and rain precipitation in every variant. Their island features are placed at a height of about Y 230 to 232, far above the normal terrain. The islands are seeded above deep ocean, so each island has a long drop beneath it. Stone growths hang from the undersides of the islands, and waterfalls pour off their edges.
In Fear Nightfall, Terralith's biomes are placed by the pack's custom biome source, which gives Terralith about 31% of land by biome count (see Terralith). Each Skylands variant is one of the biomes in that pool, so it is placed by climate like its neighbours rather than by a fixed rule.
Features
The Skylands share a set of ore and surface features with each other, plus season-specific trees and plants:
Ores: the standard overworld ore set, including coal, copper, iron, gold, redstone, lapis, diamond and the surrounding stone and dirt variants. Diamond ore appears in its normal, buried, medium and large forms, so the islands are a source of diamonds.
Butchery: the islands include Butchery's deepslate sulfur ore and its salt and sulfur generation (see Sulfur).
Sugar cane and water: sugar cane patches grow near the water, and spring water and waterfalls run from the island edges.
Floating islands: the islands are placed as up to 12 attempts per chunk at Y 230 to 232. Their undersides are extended down by stone growths.
Mobs and structures
The Skylands share the same hostile spawns: spiders, skeletons, creepers, slimes and zombies at high weight, with a small chance of Mutant Zombies, Mutant Creepers, Mutant Skeletons and Mutant Enderman. Winter replaces skeletons with strays. Summer adds Skeleton Creeper at weight 20, the only variant with that mob. Passive mobs depend on the season: autumn has sheep, cows, goats and foxes, spring has pigs, chickens and rabbits, summer has sheep, pigs, chickens, cows and parrots, and winter has goats, sheep and rabbits.
A fall from the islands is lethal unless you land in water. Water landings cancel fall damage in vanilla, so keep a bucket and a swimming plan before you jump.
Carry a light source and a means of return. The ocean below is deep, and the islands are far from the ground you started on.
Winter Skylands spawn strays in place of skeletons. Stray arrows apply slowness, so keep distance or bring a shield.
The islands have several diamond features, so they are a useful place to mine diamonds.