A Tour of the Big 14
Photos and information on the world's giant natural arches
by David Brandt-Erichsen and Jay Wilbur
On this page the Natural Arch and Bridge Society (NABS) lists all the natural arches in the world we know about that have spans greater than 200 feet. Placement on this list is based on the best data currently available to us and is subject to change pending more accurate measurements. Indeed, the ranking on this page has changed twelve times since this page was first created, and further changes are anticipated in the future, especially as additional data is obtained for arches that are outside the United States. Furthermore, the differences between the spans of some adjacent arches on the list may be within the margin of error of the measurements. As a result, the ranking presented here must be considered approximate rather than exact.
To accurately compare the sizes of natural arches, two things are needed: (1) agreement on just what points to measure, and (2) accurate measurements from those agreed-upon points. Without agreement on what points to measure, different people taking measurements may get very different results no matter how accurately the measurements are taken.
In the table below, ranking is based solely on the criterion of greatest span, where span is a dimension defined so that arches of different geometries can be consistently and accurately compared (see below for further explanation). The web pages indexed by the table below include photographs and information about each of these giant arches. You can directly link to each arch, or page through them sequentially.
The natural arches with known spans greater than 200 feet are:
|1||Fairy Bridge||Buliu River, Guangxi, China||400 ft|
|2?||Jiangzhou Immortal Bridge||Jiangzhou, Guangxi, China||280-
|3||Landscape Arch||Arches National Park, Utah||290 ft|
|4||Kolob Arch||Zion National Park, Utah||287 ft|
|5||Aloba Arch||Ennedi Range, Chad (Sahara Desert)||250 ft|
|6||Morning Glory Natural Bridge||Moab, Utah||243 ft|
|7||Gaotun Natural Bridge||Bazhou He Scenic Area, Guizhou, China||240 ft|
|8||Rainbow Bridge||Rainbow Bridge National Monument, Utah||234 ft|
|9||Sipapu Natural Bridge||Natural Bridges National Monument, Utah||225 ft|
|10||Stevens Arch||Escalante River, Utah||220 ft|
|Shiptons Arch (Tushuk Tash)||Near Kashgar, Xinjiang, China||214 ft|
|Hazarchishma Natural Bridge||Bamyan Province, Afghanistan||211 ft|
|13||Outlaw Arch||Dinosaur National Monument, Colorado||206 ft|
|Snake Bridge||Sanostee, New Mexico||204 ft|
How Are Arch Sizes Compared?
Readers should note that this is not a list of the "largest" natural arches for the simple reason that there is no precise definition of "largest" that would apply to the many different geometries displayed by natural arches. What criteria would you use for "largest" — width, height, area, volume? (The latter two would be impractical to measure as well as difficult to precisely define.) And at exactly what points would you take the measurements?
To attempt to answer these questions, the Natural Arch and Bridge Society assembled a working group of experts (including geologists, physical geographers, a physicist, and a mathematician) to come up with a set of standards and definitions for measuring natural arches. The results (some are quite technical) can be found in our Arch Info pages. No other system currently exists that permits consistent and accurate comparison of the sizes of natural arches.
For our purposes here, a less technical (and less precise) definition of the span of an arch is the horizontal extent of unsupported rock. The two illustrations below will help in understanding just what this means.
Illustration courtesy Utah Geological Survey
In the illustration above, the span would be the sum of the horizontal lines A and A'. Since this arch is not symmetrical, the span cannot be measured directly in a single line. Measuring B or C would produce quite different results.
The illustration above shows a three-dimensional view of an arch in which the dimensions differ considerably between the "front" and the "back" of the arch, which can result in wide discrepancies in reported spans. In this case, the NABS-defined span would be the maximum horizontal dimension of the most constrained part of the opening, as shown. The advantage of the NABS system of measurement is that it can be applied to arches of any geometry and will always produce consistent results. For more information, see the article on Finding the Span of Arches with Simple Shapes.
Development of this List
In October 2010 a NABS group confirmed that Fairy Bridge in China has the greatest span in the world. For many years the only two known contenders for this position were Landscape Arch in Arches National Park and Kolob Arch in Zion National Park. The most precise measurement of Landscape Arch was obtained in 2004, and the most precise measurement of Kolob Arch was obtained in 2006, finally establishing Landscape Arch as having the greater span (by a mere three feet). Fairy Bridge is now known to exceed this dimension by a surprisingly large margin (see Measurement of Fairy Bridge).
It appears likely that this list will change again in the future. There may be additional giant arches still unknown to westerners in various parts of the world such as the vast karst regions of China. One possible contender is Chuanlongyan Through-Cave (reference 1, reference 2), but there is a road and parking lot inside and the extensive construction makes it difficult to determine if the narrowest part might have been widened.
This list has a long tradition. In his 1986 book Utah Canyon Country, Fran Barnes provided a list of nine arches that were 200 feet or more in span. The list was confined to the Colorado Plateau, but no arches of that size outside the Colorado Plateau were then known. When this web page was first created in 1995, one arch from Barnes’ list (Owachomo Natural Bridge) was dropped, and another arch (Snake Bridge) was added. Here are some of the major changes to this page since it was first created:
- 2004: Aloba Arch measured and confirmed to be over 200 feet.
- 2006: Outlaw Arch discovered.
- 2007: Kachina Natural Bridge removed from list when a precision laser measurement found that it was less than 200 feet.
- 2009: Wrather Arch removed from list when a new measurement showed the span was less than 200 feet.
- 2009: Information obtained on four natural arches in China that are over 200 feet.
- 2010: Fairy Bridge confirmed as longest arch in the world; Jiangzhou Immortal Bridge found to be a contender for second place.
- 2011: Hazarchishma Natural Bridge in Afghanistan reported and measured at over 200 feet.
Now start your Big 14 Tour with a trip
to our first giant, Fairy Bridge...