Making for a nice side-trip to Kinosaki Onsen or the Town of Izushi, the Genbudō rock formations consist of complex stone patterns that are entirely natural. The miraculous rock formations are said to have appeared 6,000 years ago due to lava flows and related volcanic activity. For more details on their creation, check out the museum right nearby (600 yen for adults; open 9-5). Genbudō consists of five separate rock formations, of which Seiryū and the main Genbudō are pictured below.
Genbudō is accessible from the eponymous Genbudō train station, then a three minute ferry ride.