Off state route 535, which is the exit to CrossRoads shopping center, McDonalds, and the entrance road to DTD. About 1/3 of a mile past the McD is a subway. The shopping center is on your left. I entered beside an International House of Pancakes.
Based on size, it would almost be equal to asking where is the nearest "X" to London. WDW is 47 Square Miles, approximately twice the size of Manhattan (New York).