Detail this asset from Unity Store: Original Link
This is a paid asset, but now you can download Gothic Dungeon Pack Free.
Gothic Dungeon Pack v1.5
Texture content: Physical Based Rendering Ready! -Albedo Map -Depth Map -Specular Map -Occlusion Map -Normal Map
New update folder holds all the textures now, and few new models.
Pack Contains 80 meshes, 1024×1024 Resolution Textures And one scene ready for lightmapping.
PSD files included.