Archaeologists have uncovered a complex network of medieval tunnels beneath Gan Ha-Shelosha (Nahal 'Amal) carved into tufa rock and dated to the 14th–15th centuries. The subterranean channels funneled mountain water to drive paddle wheels that powered downstream sugar mills in barrel-vaulted chambers. Vertical crushing stones—an upper "runner" turning within a bowl-shaped lower stone—extracted cane juice for sugar production. The find, published in Water History, highlights advanced Mamluk-era hydraulic engineering and links to wider trade networks across Egypt and Asia.
Medieval Underground Waterworks Powered Mamluk-Era Sugar Industry
Archaeologists have uncovered a complex network of medieval tunnels beneath Gan Ha-Shelosha (Nahal 'Amal) carved into tufa rock and dated to the 14th–15th centuries. The subterranean channels funneled mountain water to drive paddle wheels that powered downstream sugar mills in barrel-vaulted chambers. Vertical crushing stones—an upper "runner" turning within a bowl-shaped lower stone—extracted cane juice for sugar production. The find, published in Water History, highlights advanced Mamluk-era hydraulic engineering and links to wider trade networks across Egypt and Asia.
19:42, 09.11.2025Culture
Medieval Underground Waterworks Reveal Advanced Hydraulic Engineering
Archaeologists have mapped an extensive network of engineered tunnels beneath Israel's Gan Ha-Shelosha National Park that illuminates sophisticated late-medieval manufacturing techniques. A study published in Water History reports that these waterways were cut into tufa rock along the Nahal 'Amal valley and are dated to the 14th–15th centuries, attributable to activity during the Mamluk period.
Subterranean channels, not aqueducts: Unlike the open aqueducts of Roman and Byzantine eras, these passages were hewn directly into underground rock. By channeling mountain runoff through purpose-built tunnels, medieval technicians created a locally renewable source of hydraulic power that fed a line of downstream sugar mills.
How the mills worked: The mills stood in barrel-vaulted chambers where horizontal paddle wheels were driven by water entering the tunnels. The force of water on those paddles transmitted torque to vertical crushing mechanisms above the wheel pits. A heavy upper millstone (the "runner") rotated within a bowl-shaped lower stone, mechanically crushing cane between the stones. The extracted juice was collected and then refined into sugar crystals, an important traded commodity.
Historical significance: The discovery challenges the stereotype of a technologically stagnant Middle Ages. Instead, it demonstrates deliberate hydraulic engineering, integrated industrial architecture, and production systems that linked local manufacture to wider trade networks across Egypt and Asia under Mamluk rule.
Credit: Azriel Yechezkel / A. Frumkin et al., Water History. Reporting on the find was also carried in Men's Journal.
Implications: These underground installations provide new evidence for organized industrial activity, specialized labor, and regional economic integration in the medieval eastern Mediterranean. Ongoing study of the tunnels and mills should refine dating, technological details, and connections to broader trade routes.