Translation of subordinado

In the meantime I am listening to some Spanish CDs. They are intended for the car, but no one can tell you when to listen to it, how many times and how often. Please understand that I work a lot.
The climb was much exhausting than I had presumed. I had forgotten that we were at high altitude where there is less oxygen and that every step required double effort. It was a great exercise.
Puerto Madryn was a boring city, but it was the hub to see the Peninsula Valdes, a nature reserve listed as a World Heritage site by UNESCO. We did not know what to expect but new that we would see Pinguins