Qinling Mountains in the context of "Shaanxi"

Guanzhong (Chinese: 关中, formerly romanised as Kwanchung) region, also known as the Guanzhong Basin, Wei River Basin, or uncommonly as the Shaanzhong region, is a historical region of China corresponding to the crescentic graben basin within present-day central Shaanxi, bounded between the Qinling Mountains in the south (known as Guanzhong's "South Mountains"), and the Huanglong Mountain, Meridian Ridge and Long Mountain ranges in the north (collectively known as its "North Mountains"). The central flatland area of the basin, known as the Guanzhong Plain (关中平原; pinyin: Guānzhōng Píngyuán), is made up of alluvial plains along the lower Wei River and its numerous tributaries and thus also called the Wei River Plain. The region is part of the Jin-Shaan Basin Belt, a prominent section of the Shanxi Rift System, and is separated from its geological sibling — the Yuncheng Basin to its northeast — by the Yellow River section southwest of the Lüliang Mountains and north of the river's bend at the tri-provincial junction among Shaanxi, Shanxi and Henan.

The name Guanzhong means "within the passes", referring to the four major mountain pass fortresses historically defending the region. The region was the traditional heartland of Qin state during Zhou dynasty and thus often nicknamed the "800 li of Qin land". The Yellow River, Lüliang Mountains and the eastern end of the Qinling separate the region from the (then) politically orthodox Central Plain, which is located east of the strategic Hangu Pass and therefore was historically referred as the Guandong ("east of the pass") region by the Qin people, who later conquered the eastern states and unified China as a centralized empire — the Qin dynasty — for the first time during the 3rd century BC. Afterwards, subsequent prominent dynasties such as the Han and Tang (both considered China's historical golden ages) also had the crownland established in the Guanzhong region.

The Liupan Mountains (Chinese: 六盘山; pinyin: Lìupán Shān) are a mountain range in northwestern China, located mostly in southern Ningxia Hui Autonomous Region. The range marks the southwestern boundary of the Ordos Basin.

Its southern section is known as Mount Long (Chinese: 陇山; pinyin: Lǒng Shān), which strides southeast through eastern Gansu and western Shaanxi province before joining into the Qinling Mountains, giving rise to regional names like "Longxi" (陇西, lit. "west of Mount Long"), "Longdong" (陇东, "east of Mount Long", referring to the Jing River valley basin region around eastern Pingliang, southern Qingyang and northern Xianyang) and "Longnan" (陇南, "south of Mount Long"). It is the western boundary of the Guanzhong Plain, and is also the source of the Qian River (千河), a left tributary of the Wei River that flows through the prefectural city of Baoji.

Shaannan (simplified Chinese: 陕南; traditional Chinese: 陝南; pinyin: Shǎnnán) or Southern Shaanxi refers to the portion of China's Shaanxi province south of the Qinling Mountains. Its name derives from the province's abbreviation "Shaan" (陕) combined with the word "Nan" (南, lit. "south"), its geographical location within the province.

In the Yuan Dynasty, the area began to be merged with what is the Guanzhong Plain to form Shaanxi province. The Qinling Mountains, as a geographic barrier, has also created major differences in climate, cultural traditions and dialects between Shaannan and the other parts of Shaanxi, and thus there is some similarity between Shaannan and Sichuan.

Hangu Pass or Hanguguan was a fortified gateway that commanded the strategic mountain pass between the Yellow River and Qinling Mountains, forming the main choke point on the only land corridor between the Central Plain and the Guanzhong region. The pass restricted access into the lower Wei River valleys, where the heartland of the state of Qin and the unified Qin dynasty were located, as well as the subsequent dynasties of Han, Sui and Tang.

The Hangu Pass lies on the south (right) bank of the Yellow River, 60 km (37 mi) downstream of its eastward bend out of the Ordos Loop. It was built by the state of Qin in 330 BC and had been the site of many sieges and field battles during the Warring States period and early imperial eras. Due to terrain changes from bank erosions and alluvial deposition of the Yellow River over the centuries, the Hangu Pass eventually fell to ruins after losing its defensive values to the newer Tong Pass to its west, which was built near the mouth of the Wei River in 196 AD by the warlord Cao Cao.

Shu (Chinese: 蜀; Pinyin: Shǔ; former romanization: Shuh), also known as Ancient Shu (Chinese: 古蜀; pinyin: Gǔ Shǔ) in historiography, was an ancient kingdom in what is now Sichuan Province. It was based on the Chengdu Plain, in the western Sichuan basin with some extension northeast to the upper Han River valley. To the east was the Ba tribal confederation. Further east down the Han and Yangtze rivers was the State of Chu. To the north over the Qinling Mountains was the State of Qin. To the west and south were tribal peoples of little military power.

This independent Shu state was conquered by the state of Qin in 316 BCE. Recent archaeological discoveries at Sanxingdui and Jinsha thought to be sites of Shu culture indicate the presence of a unique civilization in this region before the Qin conquest.