Nan Madol (inscribed 2016, In Danger) is the only ancient city built on a coral reef: 92 artificial islets of interlocking basalt prisms (950,000 tonnes total) in the tidal flat of Pohnpei, Micronesia — the ceremonial capital of the Saudeleur dynasty (c. 1100–1628 CE). Nandauwas royal tomb has 20m walls of basalt logs, no mortar. One of the wettest and most remote UNESCO sites on Earth.

Caral-Supe (inscribed 2009) is the oldest city in the Americas: the capital of the Norte Chico civilization (c. 2600 BCE), contemporaneous with the pyramids of Giza, with 6 platform mounds (the Pirámide Mayor: 154×138×18m), sunken circular plazas, and no pottery or weapons. Chan Chan (Chimu adobe city, inscribed 1986, In Danger), the largest pre-Columbian city, is 380 km north.

Ani (inscribed 2016) is the ruined medieval capital of the Bagratid Armenian Kingdom (961–1064 CE) on Turkey’s Armenian border: the Cathedral of Ani (1001 CE, architect Tiridates — who also repaired Hagia Sophia’s dome), the Church of the Redeemer split by lightning, and the Church of St. Gregory with the finest surviving medieval Armenian frescoes. Kars, the Russian tsarist garrison town, is the base.

Ohrid (inscribed 1979/1980) is the most important Byzantine city in North Macedonia: 365 churches tradition, the birthplace of the Cyrillic alphabet (Clement of Ohrid’s Literary School, 886 CE), and Tsar Samuel’s 10th-century fortress above ancient Lake Ohrid — one of the world’s oldest lakes (1–3 million years, 200+ endemic species), shared with Albania and extended in 2019.