Mt. Oyama once had so many pilgrims that several roads from Tokyo (Edo) and surrounding areas leading to Oyama were dubbed "Oyama-do Road" (大山道).

The road named Aoyama-dori Oyama Road started from Akasaka and passed through Sangenjaya (Three Teahouses). Sangenjaya originally had only two teahouses serving pilgrims going to Oyama. A third teahouse was added to serve the many Oyama pilgrims and that's how Sangenjaya got its name.