Price 10$ on Unity Asset Store: https://assetstore.unity.com/packages/2d/textures-materials/sky/fantasy-skybox-18216
But now you can download Fantasy Skybox FREE.
Fantasy Skybox v1.2.3
Fantasy Skybox contains 34 high-quality skybox. There are hand-painted textures for sun/sunless and moon/moonless. Demo scenes let you navigate through all skyboxes to find which one is the best for your game.
• High-quiality hand-painted textures.
• Contains 34 skyboxes.
• Contains Sun and Sunless skyboxes.
• Contains Moon and Moonless skyboxes.
• Contains demo scene and sample scripts.
• Supports all build player platforms.
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