It was just before dawn and we were deep in the jungle, trekking through the dense undergrowth to get to the ruins of the once great Mayan city buried somewhere deep within. In the darkness of the rainforest your mind starts to play tricks on you. You start to see and hear all manner of strange things – creatures, spirits, shadows of the unknown. It was then we heard the terrifying roar of a jaguar. In one split second that sound, cutting through the background of jungle noises, and all too close at hand, shattered our illusions of self-confidence, suddenly reminding us of our own delicate mortality. We stopped, for an instant frozen with fear, before turning in our tracks and stumbling off, as fast as we could, into the vast darkness of the unknown.

      We were in one of the most beautiful places in the world, Central America, on the holiday of a lifetime, visiting the ancient Mayan ruins of Tikal in Guatemala. We were trying to reach the crumbling temples, palaces and pyramids before dawn. There we would wait for the sun to rise slowly from the surrounding greenery to cast whispers of yellow-golden light over the crumbling remains of this once great civilization, as if bringing it back to life. The jungle canopy is over 200 ft (60 m) high and yet the crumbling pyramids, some still covered in creepers and vines, reach right up through it to the heavens above. From atop one of these great mountains of human endeavour, whichever way you turn, the rainforest stretches as far as the eye can see. It could be a blanket of clouds or a vast ocean below, a beautiful ocean of green, where bright-coloured macaw and toucans sweep across golden pyramids that rise like rocks from the shore.

      It was in this