The Main Entrance to the Castle

In 1664 there were renewed rumours of war between Britain and the Netherlands and they feared a British attack on the Cape. Zacharias Wagenaer was instructed to build a five-pointed stone castle. The Castle was planned from a central point with five bastions

The Castle was completed in 1679 and is the oldest building in South Africa.  It originally stood on the beach, and it is only since reclaiming the Foreshore begun in 1943 that it is now a distance from the sea.

The main entrance faced north between bastions of Catzenellenbogen and Buuren. This caused problems with storms and the tide, and it was difficult for ox wagons to travel through the sand. A new entrance was made in 1682 between the bastions of Buuren and Leerdam and the old entrance was closed. A bell tower was constructed over the entrance in 1682.

The Fort is star-shaped and has bastions at each point, which were named after the titles of the Dutch Prince of Orange, as follows:  Oranje (south west), Leerdam (west), Buren (north), Catzenellenbogen (east), and Nassau (south east). Aside from being used as a fortress against invasion from the sea, the Castle also served as  headquarters of the Dutch East India Company and was the residence of the Governor of the Cape. In 1917 it was handed over to the South African Defence Force and is still used as the headquarters of the Cape Command.  In 1936 the Castle was proclaimed a National Monument. 

This historical building houses, among others, the headquarters of Western Province Command, the William Fehr Collection and the Castle Military Museum.

The Castle is entered through the Main Gateway. This entrance was built between 1682 and 1684 to replace the original entrance which was situated between the Buuren and Catzenellenbogen bastions. There are also two smaller rear entrances to the Castle.

 
This gateway offers a window on the past. The pediment above the entrance bears the coat‑of ‑arms of the United Netherlands portraying the crowned lion rampant with the seven staves of unity in its paw. On the architrave below are carved the arms of Hoorn, Delft, Amsterdam, Middelburg, Rotterdam and Enkhuizen. These were the Dutch cities in which the United East India Company had its chambers. The company's monogram, VOC, flanks the carvings on either side.

The two pilasters, the entablature and pediment above are built of a grey‑blue stone. Built of small yellow bricks, called "Ijsel‑stene", the entrance is a unique illustration of 17th century Dutch classicism in South Africa.