[TXnMA]

"Has anybody found this in Google Maps?"

Sorry I missed your query. The main Punggye-ri Nuke Test Site (the portals pictured above) is at

41°16'49.16"N, 129° 5'9.21"E

BTW, I heartily recommend Google Earth over Google Maps for "intel" work.

GE's (Google Earth's) "time slider" is invaluable for monitoring changes over time at a site.

BTW, for accuracy and repeatability, I also recommend setting GE's "Elevation Exaggeration"(in "Preferences") to the minimum (0.01), removing all tilt, and setting "North up" (clicking the "N" at top right).

Happy Hunting!
TXnMA
 

[dr_lew]

Thanks. I had actually found this spot, but I had a lower contrast, I think, so I didn’t recognize it. I thought the dark spot above the point labeled “Portal” in your included image looked like a “pit”, possibly created by a collapse.