<strong>Super-cyclist: </strong>78-year-old Montana woman Ethel Macdonald has been tour cycling since 2003, and estimates she's covered more than 10,000 miles across Europe and the US.
Super-cyclist: 78-year-old Montana woman Ethel Macdonald has been tour cycling since 2003, and estimates she's covered more than 10,000 miles across Europe and the US.
Grania O'Hare
<strong>Stoneybatter, Dublin: </strong>CNN caught up with her during her summer tour of Ireland. She met her Dublin host, Grania O'Hare, through Warm Showers, an online community for touring cyclists and hosts.
Stoneybatter, Dublin: CNN caught up with her during her summer tour of Ireland. She met her Dublin host, Grania O'Hare, through Warm Showers, an online community for touring cyclists and hosts.
Grania O'Hare
<strong>Guest book:</strong> MacDonald keeps photos and notes from all her guests and hosts. She says she's met close to 400 fellow travelers at home and abroad.
Guest book: MacDonald keeps photos and notes from all her guests and hosts. She says she's met close to 400 fellow travelers at home and abroad.
Ethel MacDonald
<strong>Missoula, Montana: </strong>MacDonald's home town of Missoula is a popular destination for adventure cyclists.
Missoula, Montana: MacDonald's home town of Missoula is a popular destination for adventure cyclists.
Emma Lacey-Bordeaux/CNN
<strong>Netherlands: </strong>The Netherlands is MacDonald's favorite country for cycling. In 2015, Amsterdam launched the Yellow Backie bike lift scheme as an innovative new way for tourists to see the city.
Netherlands: The Netherlands is MacDonald's favorite country for cycling. In 2015, Amsterdam launched the Yellow Backie bike lift scheme as an innovative new way for tourists to see the city.
Courtesy Yellow Backie
<strong>Denmark:</strong> "Holland and Denmark are both just made for cyclists," says MacDonald. Copenhagen is filled with traffic-free bike lanes, even leading all the way to the city's <a href="index.php?page=&url=https%3A%2F%2Fwww.cnn.com%2F2014%2F10%2F21%2Ftravel%2Fworlds-best-airport-bike-paths%2Findex.html" target="_blank">Kastrup Airport</a>.
Denmark: "Holland and Denmark are both just made for cyclists," says MacDonald. Copenhagen is filled with traffic-free bike lanes, even leading all the way to the city's Kastrup Airport.
Courtesy Sergey Kovalyov
<strong>Germany: </strong>German "drivers are so aware of cyclists and so polite," says MacDonald. Berlin (pictured) regularly appears on lists of the world's most bike-friendly cities.
Germany: German "drivers are so aware of cyclists and so polite," says MacDonald. Berlin (pictured) regularly appears on lists of the world's most bike-friendly cities.
Courtesy Fat Tire Bike Tours
<strong>Belgium: </strong>MacDonald praises Belgium for its bike amenities. <a href="index.php?page=&url=https%3A%2F%2Fwww.cnn.com%2F2014%2F07%2F10%2Ftravel%2Fflanders-cycling%2Findex.html" target="_blank">Bike tours of WWI battlefields</a> are popular, including stops at Ypres (pictured).
Belgium: MacDonald praises Belgium for its bike amenities. Bike tours of WWI battlefields are popular, including stops at Ypres (pictured).
Courtesy of Visit Flanders/Westtoer
<strong>France: </strong>A former French teacher, MacDonald started her European tour cycling in France. "The whole Atlantic coast [including Bordeaux, pictured] is really good biking," she says.
France: A former French teacher, MacDonald started her European tour cycling in France. "The whole Atlantic coast [including Bordeaux, pictured] is really good biking," she says.
Rémy Martineau/Office de Tourisme de Bordeaux