Translation of periférico

A bystander who watched the entire scene all the time decided to help me. He was an older man, around seventy, but nonetheless he went to the oldest of these kids and slapped him. The boy was sixteen.
I visited a few churches near the center and decided to climb the mountains nearby, on which there were also churches. My intention was to get a good shot at the town from above, a bird view.
The same evening we left Patagonia and flew to the capital of Argentina, Buenos Aires. We have waited a long time for this moment as we have not been in a city for almost two weeks and we usually love the city.