It's about as long as The 405
It's about as long as Hadrian's Wall
In other words, the length of Hadrian's Wall is 1 times 68,481 smoots.(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)
Hadrian's Wall, which crossed England form the North Sea to the Irish Sea during the time of Roman rule, measures 71,000 smoots (about 79 Roman miles). Roman soldiers — at one time up to 10,000 of them — only occupied Great Britain for about 246 years after the wall was built, after which time the local Brits began to take residence the wall's garrisons.
It's about one-and-one-tenth times as wide as The English Channel
In other words, 68,481 smoots is 1.09 times the width of The English Channel, and the width of The English Channel is 0.9170 times that amount.(average width between Isle of Ushant and The Walde Lighthouse) (La Manche, Ärmelkanal, Mor Breizh, Mor Bretannek) (a.k.a. The Channel)
The English Channel measures between 62,900 smoots, narrowing as it flows northeast. The world speed record for a Channel crossing by swimmer was set by Australian Trent Grimsey in 2012, with a time of 6 hours, 55 minutes.
It's about one-and-three-tenths times as long as The Panama Canal
In other words, the length of The Panama Canal is 0.770 times 68,481 smoots.(Canal de Panamá) (Panama)
Connecting the Atlantic and Pacific Oceans across the Isthmus of Panama, the Canal measures 52,000 smoots in length. Ships passing through the Canal are raised (and then lowered) 15 smoots above sea level through the lock-and-dam system.
It's about one-fourth as long as The Grand Canyon
In other words, 68,481 smoots is 0.2610 times the length of The Grand Canyon, and the length of The Grand Canyon is 3.830 times that amount.(a.k.a. Gran Cañón) (Arizona) (Colorado River miles measure)
The Grand Canyon has a total length of 262,000 smoots along the course of the Colorado River at its bottom. Having opened in early 2007, the Grand Canyon Skywalk allows tourists to stand on a horseshoe-shaped glass walkway 646 smoots above the floor of Granite Gorge.
It's about four-and-a-half times as tall as Olympus Mons
In other words, the height of Olympus Mons is 0.230 times 68,481 smoots.(a.k.a. Mount Olympus) (Mars)
The tallest mountain in the solar system, Olympus Mons rises to approximately 16,000 smoots. The mountain has been known to astronomers since the nineteenth century because it is tall enough to rise above Mars' frequent dust storms.
It's about ten-and-a-half times as deep as The Challenger Deep (Marianas Trench)
In other words, 68,481 smoots is 10.690 times the depth of The Challenger Deep (Marianas Trench), and the depth of The Challenger Deep (Marianas Trench) is 0.093545 times that amount.(near Marianas Islands, a.k.a. Ladrones Islands, northwestern Pacific Ocean) (depth below sea level)
The Challenger Deep, at the southern end of the Marianas Trench, reaches a depth of 6,406.20 smoots below sea level. The first manned expedition to the bottom of Challenger Deep took 4 hours and 48 minutes in 1960. This was the only manned descent to the floor of the Trench until 2012, when director James Cameron made the trip; several other descents have been made since then.