It's about as long as The English Channel.
(average width between Isle of Ushant and The Walde Lighthouse) (La Manche, Ärmelkanal, Mor Breizh, Mor Bretannek) (a.k.a. The Channel)
It's about nine-tenths as long as The 405.
In other words, 66.5 miles is 0.91832 times the length of The 405, and the length of The 405 is 1.0889 times that amount.(a.k.a. I-405, Interstate 405, San DIego Freeway) (Southern California)
It's about nine-tenths as long as Hadrian's Wall.
In other words, 66.5 miles is 0.89 times the length of Hadrian's Wall, and the length of Hadrian's Wall is 1.1 times that amount.(a.k.a. Roman Wall, a.k.a. The Wall, a.k.a. Vallo di Adriano, a.k.a. Vallum Aelium, a.k.a. Severus' Wall) (from North Tyneside, Tyne and Wear, England, United Kingdom to Cumbria, North West England, United Kingdom)
It's about one-and-one-fifth times as long as The Panama Canal.
In other words, the length of The Panama Canal is 0.83 times 66.5 miles.(Canal de Panamá) (Panama)
It's about four times as tall as Olympus Mons.
In other words, the height of Olympus Mons is 0.25 times 66.5 miles.(a.k.a. Mount Olympus) (Mars)
It's about one-fourth as long as The Grand Canyon.
In other words, 66.5 miles is 0.24 times the length of The Grand Canyon, and the length of The Grand Canyon is 4.17 times that amount.(a.k.a. Gran Cañón) (Arizona) (Colorado River miles measure)
It's about nine-and-a-half times as tall as Maxwell Montes.
In other words, the height of Maxwell Montes is 0.1 times 66.5 miles.(Ishtar Terra, Venus)
Maxwell Montes rises to a total height of 6.8 miles. Since Venus does not seem to have the kind of tectonic activity which gives rise to mountains on Earth, the origin of the Venusian mountain remains the subject of some dispute.