Pedro de Valdivia wasn't very creative when he mapped out Santiago, sticking to the simple grid pattern typical of almost all colonial towns. The city didn't grow much larger before the meandering Río Mapocho impeded these plans. You may be surprised, however, at how orderly the city remains. It's difficult to get lost downtown, using the Andes as your compass. They’re always to the east.
Much of the city, especially districts such as Bellavista, is best explored on foot. The subway is the quickest, cleanest, and most economical way to shuttle between neighborhoods. To travel to more distant neighborhoods, or get anywhere in the evening after the subway closes, it’s probably best to hail a taxi.