2,000-year-old tunnels found under Spanish church give insight into Roman invasion

By Moira Ritter,

17 hours ago

Deep beneath an ancient Spanish church, a set of tunnels has long been a source of curiosity. Now, after five years of excavations, archaeologists know more.

The three tunnels make a U-shape underneath the church of the convent of Sant Agustí in Castelló d’Empúries, experts with the Institut d’Estudis Empordanesos said. Combined, they are about 130 feet long, 10 feet wide and 15 feet high.

Archaeologists said the tunnels were made of opus signinum — a simple, unpatterned pavement commonly used by the Romans — and had a hydraulic mortar coating, indicating that they may have been used as cisterns for holding water. Experts estimate that altogether the tunnels could hold more than 100,000 gallons of water.

Using a sample of coal from the tunnels to conduct a radiocarbon analysis, experts determined the tunnels were built between 198 B.C. and 42 B.C., which was during the Roman Republic — and much earlier than what archaeologists expected.

During this time, the Romans used Castelló d’Empúries as a port and colony in Iberia, according to the World History Encyclopedia. In 195 B.C., the Iberians revolted before Roman armies led by Marcus Porcius Cato stopped them.

Following this defeat, the region saw a period of heavy military presence, experts at the institute said. This led to increased construction of castles, towers, residences, offices and more.

The tunnels remained in use through the 20th century, offering protection during wars, according to the archaeologists.

Castelló d’Empúries is on the northeast coast of Spain, about 90 miles northeast of Barcelona.