This is a paid asset, but now you can download 2D To 2.5D&3D Conversion Pack Free.
Detail this asset from Unity Store: Original Link
2D To 2.5D&3D Conversion Pack v1.01 (Latest version)
“If possible, please buy the package to support the developer”
This package will convert our Golden Skull Isometric and Hexagonal Tile Packs into 2.5D and 3D Tiles.
2.5D means they have no backfaces or bottoms. The sprites are projected onto a simple mesh to give you more flexibility and make it easier to setup and iterate.
You can place your Tiles in 3D space and stack and scale them for even more variety. You can use DOF and other depth based Image Effects with the tiles!
Finally free choice between orthographic and perspective cameras.
Make your worlds pop with dynamic lights and shadows!
Lightmapping may need additional setup. Unity’s standard settings were tested successfully on all 3D meshes. 2,5D Meshes may have artifacts. Version 1.01 adds 3 conversion meshes for the low isometric tiles.