Wiang Kum Kam is the buried predecessor of Chiang Mai, a 13th-century Lanna settlement founded by King Mangrai before repeated flooding pushed the capital north. Its ruins are scattered through a living suburb south of the old city, with brick chedis, temple bases, and moated-city traces appearing between lanes and houses.
It is a useful antidote to Chiang Mai's polished temple circuit. You need a bicycle, tuk-tuk, or patient driver to make sense of the spread-out remains, but the reward is a clearer view of how old Lanna history sits under the modern city.