Read & study

The source library.

Explore early cities, languages, religion, Kabbalah, alchemy, philosophy, human origins, and disputed history. Open a guide, follow its sources, and keep the next question in view.

This collection contains published introductions to the growing knowledge base. Each guide links its sources; traditions and open hypotheses retain their context.

11 of 96 source guides

Southwest Amazonia, Brazil Precolonial landscape; modeled peak around 100–300 CE

The Amazon's hidden earthworks: 432 observed, thousands modeled

A new lidar survey changes the scale of the question. Here is what researchers saw, what they estimated, and why the difference matters.

Supe Valley, Peru c. 3000–1800 BCE

Caral: a wider map of early urban life.

Visit an early urban center in Peru and learn why a shared timeline helps us compare societies without assuming a connection.

Şanlıurfa, southeastern Türkiye 9600–8200 BCE

Göbekli Tepe: monuments raised before farming towns.

Visit a hilltop in southeastern Türkiye where carved stone enclosures stand at the edge of the Neolithic, and learn how a site's dates are framed.

Southern Mesopotamia, Iraq c. 5300–4100 BCE

Ubaid: the villages before the first cities.

Meet the Ubaid period of Mesopotamia and see why one research record keeps two different date ranges side by side instead of averaging them.

Southern Mesopotamia, Iraq 4000–3100 BCE

Uruk: reading the first urban horizon.

Follow the Uruk period in southern Mesopotamia, where monumental architecture, administration, and early writing appear, and learn to read a period's dates as approximate.

Indus and Ghaggar-Hakra basins, Pakistan and India 2600–1900 BCE

The Indus cities: an era of integration.

Explore the Mature Harappan phase of the Indus civilization and see how archaeologists build a chronology from artifact sequences and radiocarbon dates rather than royal names.

Kachi plain, Balochistan, Pakistan c. 5200–4700 BCE (Neolithic cemetery, 2025 model)

Mehrgarh: when a date moves by two thousand years.

Watch a chronology dispute in progress: older literature placed Mehrgarh's Neolithic in the eighth millennium BCE, and direct radiocarbon dates published in 2025 propose a much later start.

Murghab delta, Turkmenistan c. 2250–1700 BCE (alternative model from c. 2400 BCE)

Gonur Depe and the Oxus civilization: a Bronze Age world with two clocks.

Enter the Oxus civilization of Central Asia through its largest site and learn why two published chronologies are kept as separate candidates.

Northern Sudan, Middle Nile c. 2450–1500 BCE

Kerma: an independent state on the Middle Nile.

Meet Kerma, the early Kushite center south of Egypt, and see which kinds of evidence let archaeologists describe it as an independent urban state.

Konya plain, central Anatolia, Türkiye c. 7400–6200 BCE (Eastern mound)

Çatalhöyük: a town without streets.

Visit two mounds on the Konya plain where densely packed houses were entered from the roof, and learn to keep each claim with its mound and level.

Jordan Valley, Palestine c. 10,500 BCE onward

Jericho: eleven thousand years in one mound.

Tell es-Sultan preserves twenty-nine phases of occupation beside a spring. Learn why a site's oldest date must not be borrowed for its youngest walls.