Route 17 runs along the western edge of Harriman State Park . In an earlier incarnation, Harriman was mining country, and its mountains are still pocked with mine shafts and foundries. A small museum documenting the area’s mining history now stands at the Clove Furnace Historic Site (Clove Furnace Rd., off Rte. 17, Arden, 845/351-4696, 8 a.m.–noon and 1–5 p.m. Mon.–Fri., free admission).
Just behind the museum is the romantic, ivy-covered Arden House, which served as the residential estate of the Harriman family until 1972. Local lore has it that Edward Harriman built his mansion on this mountain site because he’d been shunned by the exclusive nearby community of Tuxedo Park, and wanted his wife to be able to look down on it daily.
Continuing south on Route 17, you’ll come to Route 17A. Travel west on the road about two miles to reach the dark, quiet woods of Sterling Forest State Park (845/351-5907, open dawn–dusk). The park is best known for the popular New York Renaissance Festival (914/351-5174 after June 1, www.renfair.com , adults $19, children 5–12 $9) that is presented weekends August–September. During the festival, which attracts about 175,000 visitors annually, knights in shining armor joust on horseback, minstrels strum love songs, a human chess game is played, and Shakespearean plays are staged. A special Short Line bus leaves for the festival from Manhattan  (212/736-4700 or 800/631-8405).
Farther south on Route 17, you’ll catch a glimpse of Tuxedo Park. Watch for a high stone wall and gatehouse on the right. The residential community was designed in the 1880s as a millionaires’ refuge and is filled with turreted mansions. Etiquette maven Emily Post lived here for many years, and it was in Tuxedo Park that the formal dinner jacket of the same name was first introduced.