Northern Defences

The Northern Defences are the system of tunnels, galleries and batteries cut into the Rock's sheer north face over centuries to cover the isthmus, the only land approach, and they were overgrown and closed for decades before being cleared and opened. The route runs through tunnels, past gun positions and out onto ledges with the airport runway and Spain directly below. The galleries here predate the better known Great Siege Tunnels above and were dug over several centuries rather than in one campaign. Clearing them took volunteers years of work.

What you actually see

• The tunnel galleries - the passages cut through the north face.
• The gun positions - the batteries covering the land approach.
• The isthmus view - the airport and the Spanish frontier directly below.
• The recent clearance - a system reopened after decades of closure.

When to go

April to October is the mild season. Access is through the Nature Reserve ticket. Some sections close for works.

Honest expectations

Sections are unlit and uneven and a torch helps. Parts close for maintenance and clearance work continues. Access requires the Nature Reserve ticket.

Nearby

The Moorish Castle is south, and the Great Siege Tunnels are above.