Sorry to say, but if you're reading this for good news about the rock artifact, known as key_3, found in the desert area, you wont find much here. Key_3 has some strange properties - you can't pick it up but it reacts to the USE key, (e), it has glass properties, it is a func_physbox, its spawn coordinates are -13768 12032 534, and it resembles many of the types of structures this map creator has made. These random facts basically mean it is made for something, and it CAN activate something, but that does not mean it will. By this I am saying it is like a key with a hidden, if at all there, keyhole. I did not want to accept defeat so quickly so I went over every entity name on the map, and I made a list of each major name and what it does. (I'll post it in the comments). It is still possible to for there to be entities or other map objects that are just unnamed on this map, but I wouldn't spend too long trying to find it. I'll continue scanning the map for interesting things. If you have any questions or want to know anything else about the map, please ask.

P.S. - I looked into the models of the map and there is a model of a lemon, since the map creator is related to lemons via their profile picture, this was either added as a gag or it is related to an easter egg. Also, there is no key_1 and key_2