California's major urban areas normally are thought of as two large megalopoleis: one in Northern California and one in Southern California, separated from each other by approximately 350 miles (the distance from Los Angeles to San Francisco), with sparsely inhabited (relatively) Central Coast, Central Valley, and Transverse Ranges in between. Other ideas conceive of a single megalopolis encompassing both North and South, or a division of Coastal California vs. Inland California. These regional concepts usually are based on geographic, cultural, political, and environmental differences, rather than transportation and infrastructure connectivity and boundaries.