I. The location of Monkey’s home
It is commonly assumed that the Mountain of Flowers and Fruit (Huaguo shan, 花果山) is located in China. A mountain with the same name in Jiangsu province is even touted as the home of the Monkey King. However, this is not the case within the novel’s narrative. The mountain is described as an island that “constitute[s] the chief range of the Ten Islets and form[s] the origin of the Three Islands”  and that it is situated “at the border of the small Aolai Country [Aolai guo, 傲來國], which lies to the east of the Eastern Purvavideha Continent [Sk: “Surpassing the body”; Ch: Dong sheng shen zhou, 東勝神洲]” (Wu & Yu, 2012, pp. 100 and 102). The distance between the island and Aolai is stated to be two hundred li (62 miles / 100 km) of open water. 
The cosmic geography of Indian Buddhism places Eastern Purvavideha, along with the Western Godaniya Continent (Sk: “Using Cattle”; Ch: Xi niu he zhou, 西牛賀洲), the Northern Uttarakuru Continent (Sk: “Unpleasant Sound”; Ch: Beijuluzhou, 北俱盧洲), and the Southern Jambudvipa Continent (Sk: “Rose-Apple”; Ch: Nan shan bu zhou, 南贍部洲) around the four respective faces of Mt. Sumeru (Ximi shan, 須彌山; Miaogao shan, 妙高山), a giant mountain that serves as the axis mundi of the cosmos, as well as the abode of assorted gods and sages (Robert & David, 2013, p. 869) (fig. 1). While said geography traditionally associates Southern Jambudvipa with India, or the known world to the ancient people of South Asia (Robert & David, 2013, p. 377), the novel places the “Land of the East” (Dongtu, 東土) within the continent and associates India with Western Godaniya (Wu & Yu, 2012, pp. 204-205). Most importantly, when Monkey goes in search of a means of escaping death, he sails from Eastern Purvavideha to Southern Jambudvipa (Wu & Yu, 2012, p. 108). This means he sails to China.
I suggest the author-compiler of Journey to the West supplanted the traditional geography because Jambudvipa is associated with the “known world” according to Chinese readers and India is located to the west of the Middle Kingdom, which explains why South Asia is placed in Western Godaniya.
II. Wukong studies in India
Failing to find a teacher in Jambudvipa, Monkey sails further onto the Western Godaniya continent where he discovers the sage Subhuti (Xuputi, 須菩提). Upon meeting the primate, the sage asks him, “[H]ow is it that you mention the East Purvavideha Continent? Separating that place and mine are two great oceans and the entire region of the Southern Jambudvipa Continent. How could you possibly get here?” (Wu & Yu, 2012, p. 114). This means Wukong studies elixir arts not in China but India.
Fig. 1 – A diagram showing a bird’s-eye view of sacred Buddhist geography (adapted from Robert & David, 2013, p. xxix) (larger version). Fig. 2 – A detail of Subhuti from a woodblock frontispiece appearing in an 868 CE copy of the Diamond Sutra (larger version). This document is the oldest known dated printed book in the world (full woodblock).
III. The origin of Subhuti
The Buddho-Daoist sage Subhuti is based on one of the historical disciples of the Buddha. The historical Subhuti (fig. 2) was considered the most accomplished of the Buddha’s students in meditating on the concept of “loving-kindness” (Pali: Metta; Sk: Maitri), or wishing for the happiness of others (Robert & David, 2013, pp. 518 and 861-862). Most importantly, he was also famed for contemplating “emptiness” (kong, 空), a subject with textual interpretations ranging from ridding oneself of sexual desires to “the absence of a falsely imagined type of existence” (Robert & David, 2013, pp. 872). Shao (2006) suggests the Buddho-Daoist master was modeled on the historical disciple “to evoke a scriptural tradition that identifies Subhūti as the Buddhist at his best, one having the spiritual and intuitive approximation to ’emptiness’ (sunyatā) that the Chan Buddhists value tremendously” (p. 723). He continues:
Is it then possible that what the novelist tried to highlight with Subhūti’s name was his reputation as the epitome of emptiness? We can certainly find ample textual evidence to support this line of thinking. Although Monkey’s Taoist realization is worthy of heaven, his Buddhist given name Wukong, or Awaken to Emptiness, obviously represents Subhūti’s Buddhist heritage, for the name is exactly what distinguishes Subhūti in the Buddhist tradition. What gives proof of the power and vitality of this bequest is the fact that “emptiness” constitutes the core of Monkey’s religious being (Shao, 2006, p. 724).
1) These places are famous in Chinese mythology for being the homes of immortals.
2) The original passage says “across two hundred miles of water” (Wu & Yu, 2012, p. 131). However, the original Chinese uses li (里), which is a roughly one-third of a standard mile. I have changed the information accordingly.
Robert, E. B. J., & David, S. L. J. (2013). The Princeton Dictionary of Buddhism. Princeton University Press.
Shao, P. (2006). “Huineng, Subhūti, and Monkey’s Religion in Xiyou ji,” The Journal of Asian Studies, Vol. 65 (No. 4), pp. 713-740
Wu, C., & Yu, A. C. (2012). The journey to the West: Volume 1. Chicago, Illinois: University of Chicago Press.