Deep within the jungles and underground caves of Quintana Roo, along the Caribbean coast of Mexico, the crystal-clear blue waters of the cenote entice visitors to enter their cool depths. These ancient cenotes were essential to the survival of the Mayan people who believed them to be sacred gateways to the underworld below.

Escape the heat and hustle of the city and delve down 52 stone steps into an underground cavern, just next to the Hagia Sophia in the historic center of Istanbul.

This grand cemetery in North London’s borough of Camden first opened its gates in 1839 and has since become the final resting place for around 170,000 individuals buried within 53,000 graves.

Welcome to the mind of Viktor Wynd. Delve down a steep spiral staircase, underneath an Absinth bar in East London, and you will find a unique collection of curiosities both interesting and macabre.

The theatre was connected by doors to the women's ward at the hospital from where patients would be brought into surgery, blindfolded, and held down by several men on the wooden table, ready for their operation.

‘Stop! Here is the empire of death’ reads the inscription above the entrance into the Paris catacombs where over 7 million Parisians now lie.

The Red Sand Sea forts form part of the Maunsell Sea forts and constitute one of the three defensive structures built in the Thames estuary.