I think I've figured it out. Remove unguided exploration and replace it with guided exploration. Instead of the player traveling the world and expecting to find interesting things wherever they go, the player has a specific list of things and a specific way to find them.
One method will probably be pictures like the ones taken by Zelda in botw. The player sees these 3D screenshots from the menu and then tries to find where they were taken in the world. Another method will probably be geometry based. Have a statue that points to a treasure, have a sphere of rocks with a treasure at the center, etc. The player knows from the menu exactly where the clue is and exactly what the clue means, but they have to demonstrate an understanding of the fourth dimension in order to find the reward.
These methods should be far better since the world can stay fairly sparse while still pushing players to visit more places than just the beast locations.
One method will probably be pictures like the ones taken by Zelda in botw. The player sees these 3D screenshots from the menu and then tries to find where they were taken in the world. Another method will probably be geometry based. Have a statue that points to a treasure, have a sphere of rocks with a treasure at the center, etc. The player knows from the menu exactly where the clue is and exactly what the clue means, but they have to demonstrate an understanding of the fourth dimension in order to find the reward.
These methods should be far better since the world can stay fairly sparse while still pushing players to visit more places than just the beast locations.