After a few years of using a particular brand of camera I find it difficult to spell the word "cannon" correctly. :)
Don't be fooled - this isn't Cape Town's Noon Day Gun. (You know, the cannon on Signal Hill that's gone kaboom at noon almost every day since it's placement in 1902). To be honest - I last visited the Noon Day Gun when I was a young kid. In fact, I can actually hardly remember the visit! Since then Kerry-Anne and I have made two attempts to see the cannon fire - the first was on a Sunday, and the second on a public holiday... the two days on which the Noon Day Gun takes a break!
This particular cannon is found on Tygerberg Hill and was presumably used as a signaling cannon to alert farmers as to the presence of new ships in the harbour.