This synoptic view of Houston extends from the Astrodome (bottom center) to the highway encircling Conroe to the north. Easily identifiable are such major thoroughfares as northeast-southwest-trending U.S. Highway 59 (Eastex Freeway), generally north-south-trending Interstate Highway 45, the outer Sam Houston Tollway (Beltway 8), and north-south-oriented Hardy Toll Road. The central business district is the point of convergence for all the major highways. The highly industrialized Houston Ship Channel, the eastern extension of Buffalo Bayou, winds eastward from downtown toward Galveston Bay. Apparent are George Bush Intercontinental Airport (middle of photograph); muddy Lake Houston to the east; and dark concentrations of lands, forested primarily by pine trees, to the north.