What is the Slime Shaft

Hi I dont know if this is the right catagory but I saw another post talking about some “slime shaft” in BP. Can someone take a screenshot of it and send it in comments I need help thanks.

It is a shaft in the Blast Pit map.
more here How Deep is Black Mesa?

more slime pit here https://www.ign.com/wikis/half-life/Blast_Pit
and here https://strategywiki.org/wiki/Half-Life/Blast_Pit

Is this the slime pit?