Come and visit Europe's biggest fortress

Sant Ferran Castle surveys from its watchtower the centuries of history it has been through since Ferdinand VI ordered it to be built in 1751. To get there, take the Pujada del Castell road and leave your car parked on the open area you'll find before getting to the first guard posts.

You will soon see that it's an impregnable construction standing in a privileged spot. It was in fact the arrival of French troops in the second half of the seventeenth century and the beginning of the eighteenth that made it necessary to have military facilities at that border location.

Go into the castle through the monumental gateway and then walk around the 3.2 kilometres of walls  enclosing the fortification's 32.5 hectares of space inside. If you have time and an interest in knowing the full history of the place, ask for an audio-guide at the entrance: if you follow what it says, you will be able to discover every corner of the fortress, step by step.

You'll be taken aback by the splendour of the parade ground before going into the fortresses' buildings, which were still used for military purposes until a few years ago. Standing on the walls at their highest point, you will see the 5 km of ditches surrounding the castle; and deep inside it you'll find the tanks, which can hold up to nine million litres of water. Indeed all the figures are stunning when examining this, one of the world's largest fortified strongholds.

The parade ground.

The castle can accommodate a garrison of 6,000 men and 500 horses, and in its day it was regarded as a model of military architecture. Nowadays the soldiers have been replaced by visitors, enjoying the chance to explore all the striking features of a fortress whose characteristics make it unique.