So as I told last September I was working on map which combined 2 discontinued projects. I changed the name from mp_combined to mp_sierra.
I have a few reasons to this which I will get into more when I actually release the map.
For now here's just some screens I took from the most up-to-date version.
I'll give you a more thorough look once I get around to making the preview video for this map.
Also I got this pretty old short video of one of the "secret" bhops in the map.
Release I hope will be this year. You never know these days..