It's about 5,500,000,000,000 times as long as The Volga.
In other words, the length of The Volga is 0.0000000000001790 times 641 parsecs.(a.k.a. Волга, a.k.a. İdel (Идел), a.k.a. Атăл (Atăl), a.k.a. Edil, a.k.a. İdil, a.k.a. Рав (Rav)) (from the Valdai Hills, Tver Oblast, Russia through the Caspian Sea)
The largest river in Europe, the Volga river runs 0.0000000001140 parsecs in total length. World War II's Battle of Stalingrad between the Nazi Germany and the Soviet Union, which resulted in nearly two million casualties, was fought in part for control of the river.
It's about 5,500,000,000,000 times as long as The Oregon Trail.
In other words, 641 parsecs is 5,670,000,000,000 times the length of The Oregon Trail, and the length of The Oregon Trail is 0.0000000000001760 times that amount.(from Independence, Missouri to Oregon City, Oregon)
The historic Oregon Trail stretched 0.0000000001130 parsecs across five (sometimes six) states in the western United States. In the early years of the Trail's existence, the trip was estimated to have taken an average of 160 days.
It's about 7,000,000,000,000 times as long as The Danube.
In other words, 641 parsecs is 6,940,000,000,000 times the length of The Danube, and the length of The Danube is 0.0000000000001440 times that amount.(a.k.a. Donau, a.k.a. Dunaj, a.k.a. Dunav, a.k.a. Duna, a.k.a. Дунав (Dunav), a.k.a. Dunărea, a.k.a. Дунáй (Dunay), a.k.a. Tuna) (from Breg Martinskapelle, Black Forest, Germany through the Danube Delta, Romania)
The Danube river runs 0.00000000009240 parsecs in total length. Intersecting Vienna, Austria; Bratislava, Slovakia; Budapest, Hungary; and Belgrade, Serbia, the Danube touches more capital cities than any other river.
It's about 8,500,000,000,000 times as long as The Colorado River.
In other words, 641 parsecs is 8,490,000,000,000 times the length of The Colorado River, and the length of The Colorado River is 0.0000000000001180 times that amount.(a.k.a. Aha Kwahwat, a.k.a. Grand River, a.k.a. Tizon River, a.k.a. Tecon River, a.k.a. Tison River) (from Grand Lake, Colorado through the Gulf of California)
The Colorado River runs 0.00000000007550 parsecs in length. Along this length, the river descends from its source, approximately 0.00000000000008910 parsecs above sea level in the Rocky Mountains, to its mouth in the Gulf of California.
It's about 15,000,000,000,000 times as long as The Rhine.
In other words, the length of The Rhine is 0.00000000000006670 times 641 parsecs.(a.k.a. Rhein, a.k.a. Rijn, a.k.a. Rhin, a.k.a. Rain, a.k.a. Reno, a.k.a. Rhenus, a.k.a. Ryn) (from near Reichenau, Switzerland through Hoek van Holland, Rotterdam, Netherlands)
The Rhine river runs 0.00000000004280 parsecs in total length. The World War II Battle of Arnhem, as memorialized in the 1974 book and 1977 movie A Bridge Too Far, was the first of several attempts to capture key bridges across the Rhine, beginning with the Arnhem Bridge in the Netherlands.
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.