Photographer David Clifford has captured the world's most dogged runners doing what they love in the most remote and unforgiving environments.
The Battle Box: Singapore
Underneath Singapore’s main city park lies another intriguing second world war site. The Battle Box was the British command headquarters during the fall of Singapore and consists of 22 bomb-proofed underground rooms linked by dingy corridors.
The Battle Box has been spruced up a bit in recent years and is now a big tourist attraction. The cramped old HQ is packed with displays about Singapore’s role in the war and how the city was captured by the Japanese. There is also plenty of antique military equipment to gawk at.