Buzz off stalker, we don't let every loser go through!
The Agrorprom Underground is a network of tunnels that lie beneath the Agroprom factory. Whenever you enter, there will always be a gang of bandits in the entryway, so make sure you have a good stock of ammo and decent armor before entering. It is a relatively small area with no much to explore the first time when you go in to find Strelok's stash. It is also somewhat discouraged that you hang around because of the military who reside in the deeper parts.
However on your second venture in when you go to look for Doctor there is a hallway full of electro anomalies. Go through it with caution and you will find up to seven flashes and at least one moonlight! Then proceed down the stairs and avoid the fruit punch anomalies and usually you will find a good number of other artifacts, but watch out for bloodsuckers! There is also a stash on one of the ledges in the main hallway that contains at least one urchin and posibly a thorn as well. Within the room where Strelok's stash is located it is recommended on the first trip you make to pick up the fireball artifact (point your crosshairs at the floor near the red glow to pick it up) and also smash the boxes around the giant pipe until you find the one containing the Stalker suit, which is much better than the leather jacket you're probably wearing.