Translation of horrendous in German

As it was the primary attraction for all tourist we were "escorted" by a few thousand other visitors. Our guide Samuel informed us about the ancient history of this special place.
Our bus was completely full and we were the only Europeans on our tour. There were also Americans and people from South Korea. The driver took us to a place called Tam Coc. He drove like an idiot.
In Colorado there are amazing mountains, belonging to the Rocky Mountains and in New Mexico you have the really gorgeous desert areas. Some other states there have also large desert areas.