Things to see
Phra Chulachomklao Fort features seven cannons which were once state of the art products. Normally, the cannons are hidden in their holes. They are hauled up by the hydro-pneumatics system at the moment of aiming and were lowered to their base after the shot. That is why they are called "Disappearing Carriage" or "Disappearing Guns" in English and "Puen Sua Mop" in Thai, meaning crouching tiger guns.
The cannons were officially fired for the first time in the "Rattanakosin Era Year 112 Incident" to protect Thailand's sovereignty from the French invasion. The event occurred at dusk on 13 July 1893, barely one month after the Chulachomklao Fort was completed. During the engagement, the Disappearing Guns joined six Royal Thai Navy ships in bombarding the French ships "Inconstant" and "Comete" that were attempting to sail up the Chao Phraya River to join the gunship "Lutin" that was already moored in Bangkok.