Fortress of Almeida

Fortress of Almeida

A star upon the land

Seen from above, the fortress of Almeida is one of the most astonishing sights in Portugal: not a tall castle with towers, but a giant twelve-pointed star pressed into the earth, its low walls and deep ditches forming a perfect zig-zag pattern. Inside the star sits the little town of Almeida, in the high border country of north-eastern Portugal, just a few kilometres from Spain. This is a castle from the age of gunpowder, built not to rise above attackers but to outsmart their cannon.

Why a star?

For most of history, castles were built tall, with high walls and towers. But once powerful cannon appeared, tall walls became a problem — they made an easy target and could be smashed to rubble. So military engineers invented a clever new kind of fortress: the star fort.

Almeida's low, thick, angled walls were designed to absorb cannonballs rather than shatter, and the pointed bastions at each corner of the star allowed the defenders to fire along every wall, so that no attacker could approach without being caught in the crossfire. A wide dry moat and outer defences made the place even harder to storm. Built mainly in the 1600s and 1700s, Almeida is one of the best-preserved star forts anywhere in Europe.

A prize on the frontier

Because it guarded one of the main roads between Spain and Portugal, Almeida was fought over again and again. Whoever held it controlled the gateway to the north of Portugal, so armies on both sides longed to capture it.

The fortress played a dramatic part in the Peninsular War in the early 1800s, when Portugal and its British allies fought against the armies of the French emperor Napoleon. In 1810 the French laid siege to Almeida. The defenders might have held out for months — but disaster struck. A trail of gunpowder, or perhaps a lucky enemy shell, set off the fort's main powder magazine in a colossal explosion. The blast killed hundreds, wrecked the heart of the town and forced a quick surrender. The British and Portuguese later won the fortress back.

A town inside a fort

Even today, the people of Almeida live inside the star. To enter the town you pass through long, tunnel-like gateways cut through the great earthen ramparts, designed so that no enemy could rush straight in. The streets, houses and church all sit within the protecting points of the star, making Almeida one of the most unusual towns in Portugal.

Restored and protected

The fortress is now a national monument, its walls, gates, ditches and even some of the rebuilt powder stores carefully preserved. Visitors come to marvel at the geometry of the design and to learn the dramatic story of the great explosion.

Visiting today

Visitors can walk the full circuit of Almeida's star-shaped ramparts, explore the deep ditches and the echoing gate-tunnels, and look out across the border country toward Spain. Inside, the quiet streets and the marks of old sieges tell of centuries on the frontier. Almeida is a castle of a completely different kind from the towered fortresses of earlier ages — a brilliant, deadly star built for the age of cannon.