The gun is made of 22 000 kgs of metal and has the ability to disappear underground.
Cape Town tour guide Matt Weisse, one the few people to have seen it close up, gave News24 exclusive insights.
Cape Town has an array of sights that make it one of the most visited cities in the country.
The mountains, the beaches and the cuisine also attract tourists from all corners of the world.
However, on a hill located between the V&A Waterfront and Green Point Stadium is a small piece of hidden history. [The gun] is ancient. It s from 1880. It s made of 22 000 kg of metal that could just disappear under the ground, Cape Town tour guide Matt Weisse told News24.