Cusco

Cusco was the capital of the Inca Empire, which at its height in the early 16th century stretched further along a single continuous landmass than the Roman Empire ever did, reaching from modern-day Colombia to central Chile. The city's Inca stonework, particularly the massive, precisely interlocking blocks still visible in foundations throughout the historic center, remains famous for a level of precision — gaps too narrow to fit a knife blade between stones, achieved without mortar — that still isn't fully understood by modern engineers given the tools available at the time.

Spanish colonizers built directly on top of that Inca foundation after conquering Cusco in 1533, and the result is a city where colonial churches and buildings sit literally atop Inca stonework — Cusco Cathedral and the Qorikancha, once the Inca Empire's most important temple dedicated to the sun god Inti, both display that layered construction clearly, colonial architecture rising from Inca foundations that repeated earthquakes have proven far more resilient than the structures built on top of them.

Sacsayhuamán, a massive fortress complex on a hill overlooking the city, is itself a major Inca site independent of Machu Picchu — some of its stones weigh over 200 tons, moved and precisely fitted using methods still debated by archaeologists, and its scale rivals anything found at the more famous ruins two hours away.

At roughly 3,400 meters above sea level, Cusco's altitude is a genuine practical concern rather than a minor inconvenience — most visitors experience some symptoms of altitude sickness on arrival, and spending at least one or two days acclimatizing before any strenuous activity, including the Machu Picchu trip itself, meaningfully reduces the risk of more serious symptoms.

The Sacred Valley, stretching northwest of Cusco along the Urubamba River, holds Pisac and Ollantaytambo, two of the most significant remaining Inca towns and terraced agricultural sites in the region — both work well as a single guided day trip, and Ollantaytambo also functions as the main departure point for trains continuing on to Machu Picchu itself.