From Oracle Junction, Hwy-77/Oracle Road winds around the western Catalina Mountains, following a series of one-way surface streets into compact downtown Tucson. The fastest way around Tucson is I-10, which runs diagonally along the western and southern edges of the city, while some of the more interesting “old road” routes around town include the Miracle Mile, north of downtown, and 6th Avenue, the main highway before the Interstate was built. South of Tucson, 6th Avenue becomes the Old Nogales Highway, the old road to Mexico, which veers in various alignments among extensive pecan groves while crisscrossing I-19.