The Great Wall of China.
Victoria Falls in Zimbabwe.
The Inca Trail to Machu Picchu in Peru.
The Loch Ness in the Scottish Highlands.
Tropical North Queensland, not far from the Great Barrier Reef.
Helen Pollard has completed a marathon or 30-kilometer race in each of those locations, all part of her quest to compete in a long-distance race on all seven continents.
Pollard and her 27-year-old son, Dan May, hail from the Australian island of Tasmania, the world's 26th-largest island with a population of more than 530,000. Although their home is filled with natural beauty, they both love to explore the world.
Marathons give Pollard, and more recently May, a great excuse to travel and make international friends.
"Running is a great way to see things and meet people," Pollard said. "Marathons and running festivals are so friendly. It's such a great way to see places."
With five continents crossed off her list in memorable fashion, she turned her attention toward North America and the United States. Boston? New York? Too obvious for the 52-year-old.
As she pondered which region to visit and which race to run, Colorado's Western Slope caught her eye.
"I met a couple of Americans from Arizona and Colorado a couple of years ago," Pollard said. "Seeing the runs they do around this area, it's amazing. It's beautiful. I did a Google search and found the Rim Rock Run."
After researching the annual Rim Rock Run, a course that takes runners up and over Colorado National Monument and ends in downtown Fruita, she was sold, as was May. She ran the half marathon and he ran the full marathon Saturday.
Despite no experience in marathons and an elevation much higher than what they're used to in Tasmania, May finished in about 4½ hours, not far behind Pollard.
"This is my first marathon," May said. "I've wanted to do one for a while. I had knee surgery a couple of years ago, so this was something I was working toward after that surgery. It's nice to have gotten it done."
May's medical history isn't as recent as his mother's.
"I had knee surgery only a couple of months ago and I've had a bit of sickness, so just finishing and being somewhere beautiful and stopping to take a few photos along the way was just brilliant," Pollard said.
The two have made the most out of their week and a half in Colorado.
They spent a couple of days in Boulder, visited the Garden of the Gods in Colorado Springs and attended a concert at Red Rocks, all items on the to-do list of any tourist to the state, let alone those from the other side of the world.
They also arrived just in time to experience the blizzard that covered much of Colorado in a blanket of snow.
Fortunately for both, the only challenges of the snow came behind the wheel. Even more fortunately, they claim drivers in Colorado are far less aggressive than those in Australia.
"Driving was the hard part," May said. "Being out in the snow wasn't that bad. It almost feels colder in Tasmania sometimes because at home, it's windy, wet and rainy all the time. It never rains like that here because we're at sea level."
Pollard was hobbled by her recent surgery and didn't have much experience with intense elevation, such as the more than 7,000 feet runners traverse along Rim Rock Drive on the monument.
She was so impressed by Colorado that she might come back to the Rim Rock Run in the future to turn her half-marathon into a full one.
"Because I've only done the half, I may come back to do the full and spend a bit longer with people and travel around, maybe to Arizona and Utah, as well," Pollard said.
Whether she returns to the Grand Valley, she now only has one continent to cross off her list: Antarctica.