Beneath the Great Wall of China, there are clandestine tunnels, where ancient military strategies lurk in the wall's hidden defences.
The pyramids of Egypt hide celestial secrets. There, the ancients have synced up their structures with the sun.
There are cryptic messages etched into the Statue of Liberty, which turn the symbol of freedom into a thrilling mystery novel waiting to be cracked.
At the heights of the Eiffel Tower there's a clandestine apartment where Gustave Eiffel, the French engineer behind the landmark escaped the hustle.
Under the Colosseum there are underground hidden tunnels, where gladiators plotted their fate.
In the heart of the Kremlin, are hidden bunkers and Cold War relics that turn Moscow's fortress into a covert labyrinth.
At the Sydney Opera House, one can uncover Jørn Utzon's architectural symphony, that turn the iconic landmark into a stage where innovation and design take a bow.