The traditional way to visit Cusco, Machu Picchu, and the Sacred Valley is all wrong. Most travelers arrive in Cusco and spend a night or two seeing Cusco. Then they take a whirlwind day tour of the Sacred Valley and then take the train from Cusco to Machu Picchu in one day.

The first thing wrong with this plan is that Cusco is at 3,400 meters (11,150 feet). Most people feel at least some discomfort from altitude sickness, which can feel like the flu and is a heck of a way to start a vacation. A much better plan is to head first for the Sacred Valley, a pastoral paradise with Southern California–like weather that is, most important, 500 meters lower. Few people get altitude sickness here.

Visiting the Sacred Valley first makes sense from a chronological perspective as well. The ruins of Ollantaytambo and Pisac are a good introduction to Machu Picchu. After understanding the Inca side of the equation, travelers then can return by train to Cusco, which is a Jerusalem-like blend of two opposing cultures, Spanish colonial and Inca imperial.

The standard one-day Sacred Valley tour from Cusco is a mistake. This tour whisks visitors through the Pisac market, lunch in Urubamba, and a visit to the Ollantaytambo ruins. Visitors usually miss the Pisac ruins, some of the finest in Peru, and also get shortchanged on Ollantaytambo.

The best plan is to start your Peru trip with 2–3 days in the Sacred Valley and then take a train from the Sacred Valley to Machu Picchu. Return can be from Machu Picchu directly back to Cusco.

As of 2010, floods had disrupted normal rail service between Cusco and Machu Picchu. As a result, all trains to Machu Picchu are now starting from Piscacucho, the last village in the Sacred Valley before the Río Urubamba plunges into the narrow gorges leading to Machu Picchu. Normal rail service from Sacred Valley towns such as Urubamba and Ollantaytambo will be restored in the near future.