Spain and Morocco have been dreaming for 40 years of a tunnel under the Strait. The project’s great enemy is called the Camarinal Sill

Spain and Morocco are accelerating studies for a proposed 42-kilometer rail tunnel under the Strait of Gibraltar.

The project would link Tarifa and near Tangier through two single-track tubes and a service gallery.

New bilateral research is focusing on seismic risk and seabed geology, especially the Camarinal Sill.

Officials say the tunnel is technically feasible in principle, but the engineering, financing, and geological challenges remain severe.