Sometimes, two beings are just destined to be together. Want proof? Look at the relationship between mountain climber Craig Armstrong and his adopted cat who loves to scale mountains, Millie. “She climbed up my back and sat on my shoulders,” Armstrong wrote on his website. “It took about four seconds to realize we were now partners and would be going on many journeys together.” First, Armstrong practiced with Millie in local parks to make sure she didn’t get injured or run off. Now, Millie goes with Armstrong whenever he goes hiking, and apparently, she doesn’t have a problem keeping up with Armstrong’s pro-level skills. Check out the photos from their adventures below.