'Penguin Highway' Video Captured by 21-Year-Old Traveler

What happens when you set up a camera on a mound of snow in the middle of a "penguin highway" in Antarctica?

A lot of bustling black-and-white action.

That's what Melissa Brennan, a junior at Arizona State University, discovered when she did just that last month on what she calls a once-in-a-lifetime trip to the frozen continent.

The trip marked a milestone for Brennan, 21, as it completed her goal of traveling to all seven continents of the world by her 21 st birthday.

"I stepped on the continent Dec. 28 and I turned 21 on Jan. 7," she told ABCNews.com. "It was unreal."

Brennan got the traveling bug as a sophomore in high school in 2007 when she traveled from her hometown of Scotsdale, Ariz., to New York City and then on to Europe with a group of other teenagers. She stayed in touch with friends from that trip and, through one of the friends, went to Greece and then, on her traveling friends' recommendation, went to Fiji and Australia and then back to Europe again.

"I never had that in mind," she said of her "seven by 21? goal. "It was something that hit me in 2010 when I was 19, and I realized that I'd traveled so much and then, right then and there, when I realized that, that became my goal."

Brennan, a journalism major, soccer player and Delta Zeta sorority member at Arizona State, started a blog to document her travels and supports her extreme mileage through internships, scholarships - which helped pay for her two stints of semester-at-sea - and help from her parents, neither avid travelers.

She made the journey to Antarctica solo, flying from Phoenix to Miami and then to Ushuaia, Argentina, the most southern city in the world. She departed from there on a ship to Antarctica, where she stayed for 13 days.

When she found herself with the rare opportunity to kayak to a penguin colony, Brennan had the idea to use her GoPro camera atop to capture the penguins as they are.

"The first time we saw one, there was one single penguin on an iceberg and we were all jumping up for joy," she said. "Then, by the end, there were thousands and thousands. They were almost like our friends and would come up and be right around us."

Brennan could not name a favorite country, or even continent, of the many she has visited, but said the chance to be one with the penguins in Antarctica made the continent the "most unique" of the seven.

"You can't go anywhere else in the world where that would happen, and not that many people can say they've done that," she said.

Brennan is already planning her next trip - to Greenland, Norway, Sweden and Iceland and the Arctic Circle - and says after she graduates she wants to spread the word about traveling the globe.

"I want to tell people how fun it is and to find ways to get other people to travel," she said. "It [travel] has been the biggest impact of my life. I don't regret any of it. I think that everyone should experience it."