From Mud to Stone

By 1664, England and the Netherlands were sliding towards war. Suddenly the Cape wasn’t just a vegetable stop - it was a strategic chokepoint. Whoever controlled it controlled the sea lane to Asia. If Britain took it, the VOC’s entire empire would be cut off from its source of wealth.

The VOC sent out a commissioner (Isbrand Goske) and a master builder (Pieter Dombaer) with a clear brief: design and build something that can actually survive a modern naval attack. They arrived with an architectural concept called a trace italienne - an Italian-style pentagonal bastion fort. This design had been revolutionising European military engineering for nearly a century already.

Medieval castles had tall, thin walls and round towers. They looked impressive, but the advent of cannon fire exposed a fatal flaw. One well-aimed shot could punch straight through a wall that had taken years to build.

Military engineers, mostly in Renaissance Italy, came up with a fix. Instead of building high, they built low and thick. The walls were so wide and heavy that cannonballs would simply bury themselves in the earth rather than breaking through. And instead of the usual square or rectangular shape, they arranged the walls in a five-pointed star, with triangular points - called bastions - jutting outward at each corner.

The clever part is the geometry. Each bastion can fire along the wall next to it, which means there is nowhere an attacker can stand that is not being shot at from at least two directions at once. Try to storm one section of wall and you are getting hit from the front and from the sides simultaneously.

For its time, if you had enough soldiers inside, it was basically impossible to take by force.

Each bastion contained its own independent gunpowder stores. This was a deliberate and clever piece of military engineering.

If one exploded - hit by enemy fire, or simply catching a spark - the others would survive intact. The Castle could lose one point of the star and still fight. It was seventeenth-century compartmentalisation, and it was brilliant.

This is the same logic that underlies modern ship design, where watertight bulkheads prevent a single hull breach from sinking the entire vessel.

The foundation stone was laid on 2 January 1666.

It took thirteen years and between 200 and 300 workers at any given time to complete. The walls rose to ten metres high and three metres thick. The foundations went three and a half metres into the ground.

Nothing about this building was built to be temporary. It was officially completed on 26 April 1679 and it is still standing today.