Ancient American cities had minor market areas in the outlying neighborhoods. The houses were spread out fairly far apart, in order to accommodate gardens and animals. There likely would have been main roads that converged to the big market in the center of town. Nephi’s tower may have looked like a pyramid of some kind and was probably made of stone. It was near the main market, which was prime real estate. This was probably the most valuable land in the City of Zarahemla, which was the capital city.
How did Nephi get that land? It was most likely inherited land from his father (Helaman2) and his grandfather (Helaman1). It was even possibly the location of Alma the younger’s (his great-grandfather), home as the chief judge of the court system. The temple was probably not far away. It was the same city and even the same neighborhood in which the Nephites gathered to hear King Benjamin’s famous speech. It is possible that this tower also served out as a look-out tower to watch for an approaching enemy.
As Nephi stood on the top of this pyramid, he apparently made enough of a spectacle of himself that a crowd gathered. There is something unusual going on here.
John L. Sorenson, “Nephi’s Garden and Chief Market,” in Reexploring the Book of Mormon: A Decade of New Research, ed. John W. Welch (Salt Lake City and Provo, UT: Deseret Book and FARMS, 1992) 236–238. “Furthermore, in some Mesoamerican cities ‘garden areas were cultivated immediately adjacent to single habitation complexes,’ and low-rising pyramidal towers were enclosed within private family compounds.”
Book of Mormon Central, “Why Did Nephi Prophesy Near ‘the Highway Which Led to the Chief Market?’ (Helaman 7:10),” KnoWhy 178 (September 1, 2016).