Takijiri-ōji is one of five major ōji (smaller shrines along the Kumano Kodō). It marks the beginning of the passage into the mountains and today serves as the trailhead for the Nakahechi route of the Kumano Kodō. It was once a grand affair, where pilgrims in the 12th and 13th centuries performed ablutions before setting out (the river waters to the right were said to have healing powers), but it's now rather humble.
It's a 40-minute bus ride here from Kii-Tanabe Station; take a Hongū- or Shingū-bound bus for Takajiri (¥960).