Timgad (UNESCO 1982) — Colonia Marciana Traiana Thamugadi, founded by Emperor Trajan in 100 CE for veterans of the Third Augustan Legion — is the finest surviving example of Roman orthogonal urban planning, preserved by Saharan sand burial from the 7th century until French excavations from 1881. The site on the Algerian steppe at 1,050m includes a triumphal arch, a 3,500-seat theatre, 14 bath complexes, a public library, and complete street grid legible in both plan and pavement.

Timbuktu (UNESCO 1988, In Danger 2012–present) reached its height under the Songhai Empire as one of the great centres of Islamic learning, with 25,000 students, 150–180 Quranic schools, and the three great mosques of Djinguereber (1327 CE), Sankore, and Sidi Yahia. The city holds an estimated 400,000+ private manuscripts and suffered deliberate destruction of 14 of its 16 sacred mausoleums during the 2012 Islamist occupation — an act prosecuted by the ICC as a war crime.

Chan Chan in northern Peru — 5 km from Trujillo — is the largest pre-Columbian city in South America and the largest adobe city in the world, covering 20 sq km. Capital of the Chimu Empire from c. 900 CE until the Inca conquest of the 1470s, its nine royal compounds with 9–12 m adobe walls and maritime-themed friezes remain on the UNESCO In Danger list due to El Niño erosion.

Tiwanaku, on Bolivia’s altiplano at 3,850 metres and 72 km from La Paz, was the spiritual and political capital of the pre-Inca Andes from roughly 500 to 1000 CE. Its Gate of the Sun — a 10-tonne carved andesite doorway bearing the relief of the creator deity Viracocha — and its Akapana pyramid are among the most important monuments of South American civilisation.

The Konark Sun Temple in Odisha, built around 1250 CE under King Narasimhadeva I, is designed as a colossal stone chariot of the sun god Surya, with 24 carved wheels (each 3 metres in diameter) and a surviving audience hall 39 metres tall. UNESCO-inscribed in 1984, it sits 64 km from Bhubaneswar and 35 km from Puri as part of Odisha’s Golden Triangle.

The Buddhist Monuments at Sanchi (UNESCO 1989) stand on a sandstone hill 46 km from Bhopal in Madhya Pradesh — the oldest stone structures in India and the most complete early Buddhist ensemble anywhere. The Great Stupa, originally built by Emperor Ashoka in the 3rd century BCE, is surrounded by four elaborately carved stone gateways (toranas) from the 1st century BCE depicting 547 Jataka tales. The site is notable for its aniconic representation of the Buddha, indicated by symbols rather than a human image.

Volubilis (UNESCO 1997) is the best-preserved Roman provincial city in the Maghreb, on the Zerhoun plain 33 km from Meknès in Morocco. Its 40-plus in-situ floor mosaics — the largest such collection in northwest Africa — survive in the rooms of the houses where they were originally laid. The city was capital of the Roman client kingdom under Juba II (married to Cleopatra Selene II) and later the first seat of the Idrisid dynasty, founders of the Moroccan royal line.

Itchan Kala, the walled inner city of Khiva (UNESCO 1990), is the most completely preserved medieval Central Asian city in existence — 10 hectares of mud-brick architecture including the unfinished Kalta Minor, the 213-column Juma Mosque and the 163-room Tosh-Hovli Palace. Unlike Samarkand and Bukhara, Khiva’s medieval urban fabric survives intact, including its street pattern and residential quarters. The city served as the Silk Road’s last active slave market until Russian conquest in 1873.

Göbekli Tepe, a UNESCO World Heritage Site since 2018, is a 11,600-year-old ritual complex built by Neolithic hunter-gatherers on a limestone hilltop in southeastern Turkey. Its T-shaped limestone pillars — up to 5.5 metres tall and 20 tonnes each, decorated with bas-reliefs of foxes, vultures and snakes — predate Stonehenge by 6,000 years. The site overturned the established view that monumental architecture follows agriculture, suggesting instead that communal ritual may have driven the agricultural revolution itself.

The Pre-Hispanic City and National Park of Palenque, UNESCO-inscribed in 1987, reached its artistic peak under Pakal the Great (r. 615–683 CE) and K’inich Kan Balam II (r. 684–702 CE); the Temple of the Inscriptions (7 platforms, 23 m tall) covers the royal crypt discovered in 1952 by Alberto Ruz Lhuillier, with its 620-glyph inscription panels — the longest Maya stone text known.