Pilgrimage
To make a pilgrimage means to undertake a journey—typically in the context of religious practice—of personal or ritual significance. The journey can be external and physical (as in the case of the pilgrims journeying to Thomas Becket's tomb in Geoffrey Chaucer's The Canterbury Tales), internal and spiritual (as in the case of Christian, who narrates his own allegorical vision in The Pilgrim's Progress, by John Bunyan), or both. The tradition is ancient: Scholars have found relics and records of various forms of it that date back into preclassical times. Most major world religions have sanctioned, or still sanction, some form of sacred travel in their practices and rituals, but pilgrimage is not purely a formal religious phenomenon. Many "pilgrimages" in modern times—arguably including such secular activities as tourism, symbolic political action, and journeys of personal self-discovery—testify to the lasting power of ritual travel as a manifestation of human yearning and the search for meaning, even in an era ostensibly dominated by a culture of scientific rationalism. Pilgrimage would seem to be as compelling a human phenomenon as ever—both as ritual and as metaphor.
Ritual and place
Primative religions tended to locate the divine in particular places—the river, the sun, the volcano, the forest, and so forth. Practically speaking, if you wanted to talk to a god, goddess, or spirit, you had to go for a visit. Pilgrimage, even when associated with modern monotheistic religions whose basic tenets asset that God is everywhere, harks back to that primitive religious impulse to identify particular places as sacred.
Even faiths such as Islam and Judaism, whose doctrines center on the idea of a universal God, manage to square that universality with particular places. The Israelites of the book of Exodus, for example, spurned the polytheism of Egypt and fled into the wilderness; eventually, though, even though their God was "everywhere," they came to carry with them a portable temple, in the form of the Ark of the Covenant and its tabernacle, which ultimately became a permanent "place" when the first Temple of Jerusalem was built around it. In Islam, the holy city of Mecca and the black stone of the Kaa'ba serve to give focus to the worship of Allah, and are places of officially sanctioned pilgrimage.