Let's face a steel hard fact here.

Indeed, there's a nest that tends to spawn rare pokemon in my area, now converted into a gym, and I can no longer tell what that nest is unless I go right next to it now.

Our area only recently got a scanner. Without it i would have zero beldum. They seem to spawn most commonly at the industrial precinct in a nearby suburb that most players wmould have no reasdon to hho into otherwise.
We used to have a raid map, that we lost due to 3 consecutive bot banwaves a while back and not enough people donating, before getting a new one as part of the current map, in that time we lost lots of players esp with the raid timer shortened to 45mins, as we were unable to arrange raids with enough time gor people to travel.