This appears to be Nambu ironware, likely manufactured in or around Morioka City, Iwate Prefecture. While there's no definitive proof, its robust construction suggests it's a high-quality iron casting product. • It has high heat retention, a characteristic of Nambu ironware, a traditional Japanese craft, and excels at keeping things warm. • The characters on the rim may be auspicious symbols like "fortune" or "prosperity," or perhaps motifs of the Chinese zodiac, making it valuable as an antique.