I was about 8 years ago. (Patreon)

An interesting find. About 8 years ago, I created my own maps for hl2, and then hl2ep2. I did not port anything, I came up with some kind of my own huge bunker, I remember there were many rooms, a dining room, bedrooms, a bar ... all this is unfortunately lost. I also built some kind of wooden house from a photo from the Internet))) And some kind of pier, it seems from Just Cause 2.  And the parking lot was partially built based on screenshots from Mafia II.

And then an arrow hit me in the knee... oh, that is. I made my first port, it was a strip club from saint row 3, I played this game for over 300 hours. Then I made apartments from ME3 and after that all my works were ports of other locations, I still have not seen anyone doing such precise transfers of locations, mostly these are just similar rooms with textures and models from hl2 or css or l4d2...

To be honest, I have no idea where all these maps are, I have only the source files stored since 2009, but the models and materials are definitely lost.

It saddens me to realize that many people think that this is just ctrl + v ctrl + c, but in fact any port, especially maps or content from games for which there is no normal toolkit, is just hellish work and it takes a lot of time.

UPD: I found in the archives for 2013 an early version of the strip club from saint row 3, still based on the left 4 dead 2 models, and it seems my own, unfortunately they are irretrievably lost (their place is error).  (Last 2 screenshots.)