Radium tamago (eggs) are par-boiled in the waters of the local onsens. These local delicacies take 30 to 60 minutes to cook at a temperature of between 63 and 70 degree. The name of these eggs is derived from the fact that Iizaka Onsen was the first place in Japan where the existence of radium was confirmed. They are usually eaten with soy sauce, or with a bowl of freshly steamed rice.
Where to buy: Iizaka Onsen Area