I finished the game, and am currently replaying it, fast traveling to the areas for relics and GPS caches etc.
Right now I got to the Research Base to finish the Sun Killer mission, but the area is sealed off by rocks. I also tried the other direction, and ended up in a trench of water where there is a climbable wall, but there is a fence blocking the upper part of the climbable wall. Am I overseeing something? it seems that both directions are blocking me from areas where there could be some totems.