A small Nichiren sect temple near the base of the Asaina Pass, built on the site where the monk Nichiren wrote his famous treatise Rissho Ankoku Ron (On Establishing the Correct Teaching for the Peace of the Land) in 1260, warning the government that natural disasters would continue unless they abandoned other Buddhist sects. The government responded by exiling him. Nichiren was right about the disasters — the Mongol invasions came soon after.
The cave where he is said to have written the treatise can still be visited. A quiet site for those interested in Japanese Buddhist history. Free admission.