The Hyrule Field Skyview Tower is behind the walls of a Bokoblin and Moblin encampment.
Access the Tower
This tower is behind the walls of a Bokoblin and Moblin encampment, and you will find a platform on the east side of the hill that you can fight your way up. Once you get past, beware of the spiked metal spheres that they throw at you on the bridge. Then fight your way into the encampment, and when the coast is clear (or you are wearing the Bokoblin Mask to go through without rousing suspicion), open the door of the tower and go in.
Map the Region
Examine the terminal to activate the teleport location here. Then step onto the glowing spot in the tower and examine it to be launched upward and map the area.