You are speaking of the NEOM Project, here is a good video about it...
Geo-economics of Saudi Arabias NEOM project
https://youtu.be/iKgwm6WKhSg
And, a video by them same creator from last month about Prince Salman...
Abdication of King Salman in Saudi Arabia
https://youtu.be/UzTBev_svWI
At least in the promotional video.