Find a 100-story skyscraper and take the stairs to the top. This will give you some preparation for walking the Inca Trail - a four-day slug up and over the Andes to the 'Lost City of the Inca' - Machu Picchu.

The Inca Trail is only one small part of the once-great Inca Road System, which covered approximately 22500 kilometres of ground and provided access to more than three million square kilometres of territory.

This extensive road network ultimately allowed the Inca Empire to flourish. It was key to distributing food and information. The Inca didn't have horses so the roads were built for foot traffic. Special runners stationed approximately every 10km along the road - with the help of coca leaves to alleviate pain and hunger - could run up to 240 kilometres a day over the trails, carrying messages from one end of the Empire to the other.

Today the most popular of the Inca roads is the Capaq Nan trail, leading up to Machu Picchu past many ruins and the rushing Urubamba River. It takes four days and traverses several high passes including Dead Woman's Pass at 4215 metres.

The Peruvian Government was concerned about erosion on the trail so have capped numbers. Only 500 people - including guides and porters - are allowed to start the trail each day. This seems like a substantial number, but during the dry season (May to September), advanced bookings (up to nine months beforehand) are an absolute must. There are around ninety tour companies based in Cusco who advertise online who take tours. It is compulsory to go with an organized tour and licensed guide. 

The reward for four days of relative hell is watching the sun rise over Machu Picchu. No matter how many photos you've seen, or documentaries you've watched, the Lost City of the Inca will blow you away. There's a tangible power and sadness that inhabits the ruins perched on top of a lonely mountain. You can't help but wish history were different so the people who built this remarkable and spiritual place were still around to explain how and why.