Li (unit) in the context of "Guanzhong"

The Great Wall of China (traditional Chinese: 萬里長城; simplified Chinese: 万里长城; pinyin: Wànlǐ Chángchéng, literally "ten thousand li long wall") is a series of fortifications in China. They were built across the historical northern borders of ancient Chinese states and Imperial China as protection against various nomadic groups from the Eurasian Steppe. The first walls date to the 7th century BC; these were joined together in the Qin dynasty. Successive dynasties expanded the wall system; the best-known sections were built by the Ming dynasty (1368–1644).

To aid in defense, the Great Wall utilized watchtowers, troop barracks, garrison stations, signaling capabilities through the means of smoke or fire, and its status as a transportation corridor. Other purposes of the Great Wall have included border controls (allowing control of immigration and emigration, and the imposition of duties on goods transported along the Silk Road), and the regulation of trade.

The mile, sometimes the international mile or statute mile to distinguish it from other miles, is a British imperial unit and United States customary unit of length; both are based on the older English unit of length equal to 5,280 English feet, or 1,760 yards. The statute mile was standardised as a unit of length between the Commonwealth of Nations and the United States by an international agreement in 1959, when the yard was formally redefined with respect to SI units as 0.9144 metres, making the mile exactly 1609.344 metres (1.609344 kilometres). For everyday use, five miles equates roughly to eight kilometres.

With qualifiers, mile is also used to describe or translate a wide range of units derived from or roughly equivalent to the Roman mile (roughly 1.48 km), such as the nautical mile (now 1.852 km exactly), the Italian mile (roughly 1.852 km), and the Chinese mile (now 500 m exactly). The Romans divided their mile into 5,000 pedes (lit. 'feet'), but the greater importance of furlongs in the Elizabethan-era England meant that the statute mile was made equivalent to 8 furlongs or 5,280 feet in 1593. This form of the mile then spread across the British Empire, some successor states of which continue to employ the mile. The US Geological Survey now employs the metre for official purposes, but legacy data from its 1927 geodetic datum has meant that a separate US survey mile (⁠6336/3937⁠ km) continues to see some use, although it was officially phased out in 2022. While most countries replaced the mile with the kilometre when switching to the International System of Units (SI), the international mile continues to be used in some countries, such as the United Kingdom, the United States, and a number of countries with fewer than one million inhabitants, most of which are UK or US territories or have close historical ties with the UK or US.
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Shahidulla, also spelt Xaidulla, (altitude ca. 3,646 m or 11,962 ft), was a nomad camping ground and historical caravan halting place in the Karakash River valley, close to Khotan, in the southwestern part of Xinjiang Autonomous Region, China. The site contains the ruins of a historical fort which was demolished by the Chinese administration of Xinjiang between 1890 and 1892. The site lies next to the Chinese National Highway G219 between Kashgar and Tibet, 25 km east of Mazar and 115 km west of Dahongliutan.

The modern town of Saitula (Xeyidula) is located next to the old fort of Suget Karaul built by the Qing administration (of China) about 10 km (30 "Chinese miles") southeast of the original site. A modern People's Liberation Army barracks named Sanshili Yingfang or Sanshili Barracks (lit. '30 li barracks') is also located here. "Sanshili Barracks" is a more common name used by motorists along the G219 highway.

Chinese cartography began in the 5th century BC during the Warring States period when cartographers started to make maps of the Earth's surface. Its scope extended beyond China's borders with the expansion of the Chinese Empire under the Han dynasty. By the 11th century during the Song dynasty highly-accurate maps drawn on grids were produced. During the 15th century, the Ming dynasty admiral Zheng He went on a series of voyages to the South China Sea, Indian Ocean, and beyond and maps for areas outside of China were produced, although world maps covering territories known to the Chinese outside of China existed as early as the Tang dynasty.

The study of geography in China begins in the Warring States period (5th century BC). It expands its scope beyond the Chinese homeland with the growth of the Chinese Empire under the Han dynasty and enters a golden age with the Han dynasty invention of the compass as one of the Four Great Inventions. The compass was then used from the 11th century during the Song dynasty, Yuan dynasty, Ming dynasty, and Qing dynasty in the study of geography. One of the most famous explorers in Chinese history was the 15th century admiral Zheng He, known for the Chinese exploration of the Pacific and his treasure voyages.