For a natural experience of a different kind, organize an outing to the bubbling pools of Daito Onsen Seatopia. This spot is known for its mineral-rich waters.
This Kakegawa naturally heated water source is a good place to start your day of sightseeing. There's plenty to experience in the vicinity, such as Hamaoka Sand Dunes, Yokosuka Ruins Of A Castle Park, and Yokoji Castle Ruins. Wander around at your leisure at Daito Onsen Seatopia before hitting up these other fine sights.