Network of underground chambers, tunnels, and passages beneath Malta's capital city, dug into limestone bedrock by the Knights of Malta following the Ottoman siege of 1565. The tunnels feature blue-gray clay waterproofing identical to material found in the Money Pit.
About This Site
Beneath the streets of Valletta lies an extensive network of underground chambers, tunnels, and passages carved into the limestone bedrock by the Knights of Malta in the decades following the Great Siege of 1565. The Ottoman attack exposed the vulnerability of the island's above-ground defences, prompting the Hospitallers to construct an elaborate underground infrastructure beneath their new capital. The tunnels served multiple purposes: military storage, protected passage between fortified positions, and cisterns for collecting and storing fresh water. The underground network demonstrates the same advanced tunnel engineering and waterproofing techniques the order had developed across centuries of fortification construction in the Holy Land, Cyprus, Rhodes, and the Mediterranean.
Connection to Oak Island
In Season 12, journalist Jean Paul Mifsud led the team into the underground passages beneath Valletta. The tunnels, dug into limestone bedrock, provided the team with a firsthand look at Hospitaller underground construction techniques. Of particular significance was the blue-gray clay lining the tunnel walls, which Jean Paul identified as a sealant used for waterproofing. Scott Barlow immediately noted that blue clay was similarly used for waterproofing inside the Money Pit on Oak Island, where it has been encountered at multiple depths during drilling operations.
The parallel between the Valletta tunnels and the Money Pit extended beyond the clay: both systems featured passages cut through rock, water management infrastructure, and deliberate sealing techniques designed to control flooding. The Hospitaller tunnels demonstrated that the engineering knowledge required to construct the Money Pit's flood tunnel system existed within the military-religious orders connected to the broader Templar and Hospitaller tradition.
Fieldwork Notes
Visited during Season 12 by Rick Lagina, Alex Lagina, Peter Fornetti, Doug Crowell, Corjan Mol, and team members. Journalist Jean Paul Mifsud guided the team through the underground passages. The team documented blue-gray clay waterproofing matching Money Pit blue clay, limestone tunnel construction, and underground cistern systems.
