Read the passage.

Our visit to New Mexico was great. Watching the sun rise over the desert is one of the greatest memories I have from any vacation. Taos, a small town that is nestled among soaring mountains, was my favorite place to visit. Skiing constantly, we flew down the sides of mountains for most of our vacation.
Which group of words from the passage is a participial phrase?

Skiing constantly
flew down the sides of mountains
nestled among soaring mountains
Watching the sun rise