Tojin Daba
The Tojin Daba site is located in the mountains about 10 kilometers from central Tosashimizu. Now covered with lush greenery, Tojin Daba was inhabited during the prehistoric Jomon period (10,000–300 BCE). The site is dotted with huge rocks up to 7 meters tall called tojin-ishi. These granite boulders were formed when magma hardened deep underground, and were eventually thrown up to the surface by tectonic activity. The tojin-ishi are solid and devoid of cracks, unlike most other granite rocks, which tend to fall apart when rain and groundwater seep into them over long periods of time.