This was on one of the old servers and was primarily built by one player (Nyuudles) when we had infinite blocks and rapid firing grapples. It’s not available to view anymore.
The Paris Games week city was built by Everbloom Studios specifically for the trailer. It was made available on the test servers for a short time, but was later replaced with a snapshot of the live servers, so that actual game world data could be used for testing releases.