PowerPyx has done a pretty good location guide for each planet. Here's a link to each individual planet. If anyone gets stuck or can't find a location, leave a comment and we'll see if we can't figure it out. Some are a pain.
Pandora - 78 Locationshttp://www.powerpyx.com/borderlands-3-pandora-all-named-loca...Promethea - 43 Locationshttp://www.powerpyx.com/borderlands-3-promethea-all-named-lo...Athenas - 5 Locations -
http://www.powerpyx.com/borderlands-3-athenas-all-named-loca...Eden-6 - 63 Locations
http://www.powerpyx.com/borderlands-3-eden-6-all-named-locat...Nekrotafeyo - 27 Locations
http://www.powerpyx.com/borderlands-3-nekrotafeyo-all-named-...Each trial, once discovered, will count as a named area as well, so once found, you will need to walk around until the name pops up on screen.
Same thing with all the slaughters, you need to travel into the slaiughters and walk around until you see the name.
If you're going to vote negative, please say why. I can't improve the solution if I don't know why it's being voted negative.