It's about 45,000,000,000,000 times as long as The Grand Canyon.
In other words, 641 parsecs is 44,300,000,000,000 times the length of The Grand Canyon, and the length of The Grand Canyon is 0.00000000000002260 times that amount.(a.k.a. Gran Cañón) (Arizona) (Colorado River miles measure)
The Grand Canyon has a total length of 0.00000000001450 parsecs 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 0.00000000000003560 parsecs above the floor of Granite Gorge.
It's about 150,000,000,000,000 times as long as Hadrian's Wall.
In other words, the length of Hadrian's Wall is 0.00000000000000630 times 641 parsecs.(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 0.00000000000390 parsecs (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 150,000,000,000,000 times as long as The 405.
In other words, 641 parsecs is 169,720,000,000,000.00000000000000000000 times the length of The 405, and the length of The 405 is 0.00000000000000589210 times that amount.(a.k.a. I-405, Interstate 405, San DIego Freeway) (Southern California)
Running from Irvine to San Fernando, The 405 runs a total of 0.00000000000377680 parsecs. The 405 is the most heavily-trafficed freeway in the United States, with an average speed as low as 8 kph during rush hours.
It's about 200,000,000,000,000 times as long as The English Channel.
In other words, 641 parsecs is 185,000,000,000,000.000000000000000000 times the length of The English Channel, and the length of The English Channel is 0.000000000000005410 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 0.000000000003470 parsecs, 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 200,000,000,000,000 times as long as The Panama Canal.
In other words, 641 parsecs is 220,000,000,000,000.00000000000000000 times the length of The Panama Canal, and the length of The Panama Canal is 0.00000000000000450 times that amount.(Canal de Panamá) (Panama)
Connecting the Atlantic and Pacific Oceans across the Isthmus of Panama, the Canal measures 0.00000000000290 parsecs in length. Ships passing through the Canal are raised (and then lowered) 0.000000000000000840 parsecs above sea level through the lock-and-dam system.
It's about 750,000,000,000,000 times as tall as Olympus Mons.
In other words, the height of Olympus Mons is 0.00000000000000140 times 641 parsecs.(a.k.a. Mount Olympus) (Mars)
The tallest mountain in the solar system, Olympus Mons rises to approximately 0.000000000000880 parsecs. 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 2,000,000,000,000,000 times as tall as Maxwell Montes.
In other words, the height of Maxwell Montes is 0.000000000000000560 times 641 parsecs.(Ishtar Terra, Venus)
Maxwell Montes rises to a total height of 0.000000000000360 parsecs. 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.