What is the conventional archaeological date of Machu Picchu (Peru), and what alternative dates have been proposed?

Conventional date: An Inca center in the Andes. It was occupied from about AD 1420 (radiocarbon, Burger et al. 2021). Activity there lasted until about AD 1532. Alternative proposals: Open question: UNESCO (World Heritage listing): What was it for? UNESCO calls it a religious, ceremonial, sky-watching and farming center. It says the exact role the site played in Inca study of the sky is still not settled.

What has been measured at Machu Picchu (Peru) in peer-reviewed studies?

Dates from the burials: A 2021 study dated bone and teeth from people buried in caves at four cemeteries around the site. The results show it was used from about AD 1420 to 1532. The date in written sources: Written sources tie the site to the Inca emperor Pachacuti, who came to power in AD 1438. That date comes from those texts, as Burger and colleagues sum them up. About 20 years earlier: The new dates show people were active at the site about 20 years before the date in the written sources. About 200 buildings: UNESCO counts about 200 structures on a steep ridge more than 2,400 m above sea level. The site became known to the outside world in 1911. Machu Picchu is the best-known site of the Inca Empire. It sits high on a ridge between the Andes and the Amazon basin. Until recently its age rested mostly on written records. In 2021 a team led by Richard Burger dated human remains from burials near the site. Their dates start about two decades before the date in the written records.

What are the stone types, heaviest block masses, and quarry transport distances at Machu Picchu (Peru)?

These are not reported in the sources cited on this page.

Sites › South America › Machu Picchu (Peru)

Machu Picchu (Peru)

📍 Where It Is Cusco Region, Peru (above 2,400 m) -13.1631°, -72.5450°

🏛️ Mainstream Date About AD 1420–1532 (radiocarbon) Excavated baseline

🧭 Leading Edge / Open Angle Open question: its exact role in Inca sky study Debated or newly revised

🪨 Heaviest Stone & Quarry Stone weights not reported in our sources Compare all 73 sites →

30-SECOND TAKEAWAY

In Plain English — The 30-Second Takeaway

What It Is:

An Inca stone town and ceremonial center high in the Andes.

What Everyone Agrees On (Measured Facts):

Dates from burials show the site was used from about AD 1420 to 1532.

🏛️ Mainstream Archaeology View:

Scholars see it as an Inca site. New dates start about 20 years before the date in written sources.

🧭 Leading Edge View:

No Leading Edge claim is tracked here yet. UNESCO says its role in Inca sky study is still open.

Site Story & Overview

Machu Picchu is the best-known site of the Inca Empire. It sits high on a ridge between the Andes and the Amazon basin.

▸ Read Full Archaeological & Engineering Context

Until recently its age rested mostly on written records. In 2021 a team led by Richard Burger dated human remains from burials near the site. Their dates start about two decades before the date in the written records.

✓ What Is Physically Measured on Site

Dated samples, laser scans, stone weights, and dug finds kept separate from opinion.

Dates from the burials: A 2021 study dated bone and teeth from people buried in caves at four cemeteries around the site. The results show it was used from about AD 1420 to 1532. [1]
The date in written sources: Written sources tie the site to the Inca emperor Pachacuti, who came to power in AD 1438. That date comes from those texts, as Burger and colleagues sum them up. [1]
About 20 years earlier: The new dates show people were active at the site about 20 years before the date in the written sources. [1]
About 200 buildings: UNESCO counts about 200 structures on a steep ridge more than 2,400 m above sea level. The site became known to the outside world in 1911. [2]

🏛️ Mainstream Archaeological View

Accepted timeline: An Inca center in the Andes. It was occupied from about AD 1420 (radiocarbon, Burger et al. 2021). Activity there lasted until about AD 1532.
Stone & hardness: Not reported in the sources on this page. Mohs hardness: not reported in our sources.
Quarry distance & alignment: Stone source not reported in the sources on this page. Orientation: Not reported in the sources on this page.

🧭 Leading Edge Proposal & Open Questions

Open question: UNESCO (World Heritage listing): What was it for? UNESCO calls it a religious, ceremonial, sky-watching and farming center. It says the exact role the site played in Inca study of the sky is still not settled. [2]

Primary Academic Sources

▸ View All Cited Primary Sources & DOIs (2 papers)

Burger, R. L., Salazar, L. C., Nesbitt, J., Washburn, E. & Fehren-Schmitz, L. (2021). New AMS dates for Machu Picchu: results and implications. Antiquity 95(383): 1265–1279. doi:10.15184/aqy.2021.99 data
UNESCO World Heritage Centre. Historic Sanctuary of Machu Picchu (list no. 274), accessed 2 November 2026 https://whc.unesco.org/en/list/274 background

Dates and stone checks are summed up in plain English from the papers above. Measured facts stay separate from opinion. Methodology.