This virtual world was created by IBM and is a total digitized version of the Forbidden city. Just make yourself an avatar (not highly customizable I must say), and walk around the marvelous gardens. If you want a more straight approach, just grab one of the guides (NPCs) that will give you a tour around the place.
That kind of use cases around virtual worlds is really amazing, while it sure isn’t photorealistic (I guess having the appropriate high-res textures would be the only reason to justify FTTH projects) it is still stunning to go wander freely in an open 3D environment, just like if you were there in real life.
Last time I went in Beijing I missed it (it is closing way too early) so it’s funny to get there from home!