Rift is a base, with a lot of wallrunning options in the Eclipse Black Ops 3 DLC map pack. You will not want to fall on this map, since it means death. In fact, you may want to use the Glitch ability to save yourself the first several times you play on this map.
You can run through a middle area and through a number of hallways on each side. I recommend running low to the wall when in the hallways and keeping your aim up, as it will allow you to get a few surprise kills.
Similar to the lobby in Spire there is a big open area with two overlooks, one at each spawn, and a lot of chances to wallrun around this open area over top of lava. Watch out if you wallrun in a transition into the middle area since it will leave you open to a lot of fire.
You can find success with almost any weapon on Rift. I still enjoy a good SMG that has OK range, but you can easily dominate this map with a good AR as long as you are careful funneling into the hallways.
The video above walks through the map, so you can learn about the various places you need to go to successfully navigate with extra caution as you move across the base.