Daedongnyeojido, or the “Detailed Map of the Great East,” is a massive map of Korea created with woodblocks in 1861 by the renowned cartographer, Kim Jeong-ho, with the aim of propagating knowledge of the territory. To make the map, Kim divided the Korean Peninsula into 22 sections from north to south, with each section spanning about 47 km (north-south) by 31.5 km (east-west). Each of these sections was then meticulously mapped in a single booklet, which could be easily folded for portability. When all 22 volumes are unfolded and laid together, they form an enormous map of Korea—6.7 meters wide and 3.8 meters long. A total of 70 engraved woodblocks, made from linden (i.e., basswood) trees and carved on both sides, were used to make prints of the map. The woodblocks were completed in 1861, but they were continually revised until 1864, when the second edition of the map was printed. The map features precise delineations of mountain ridges, waterways, and transportation routes, the latter of which are carefully plotted with dots approximately every 4 km. In addition, notable administrative and cultural areas and sites are marked with a variety of symbols comparable to today’s cartographic signs. Daedongyeojido is generally regarded as the greatest cartographic achievement in Korea before the modern period, and its detail and precision are favorably compared to modern maps made with advanced surveying equipment and techniques.