Health and Safety
You’ll likely encounter altitude sickness, known as soroche, at Cusco's 3,500-meter (11,500-foot) elevation. Drink lots of fluids, but eliminate or reduce alcohol and caffeine consumption, and eat lightly as much as possible for the first day or two. Many hotels have an oxygen supply for their guests' use that can minimize the effects. The prescription drug acetazolamide can help. Check with your physician about it (allergies to the drug are not uncommon) and about traveling here if you have a heart condition or high blood pressure or are pregnant.
Warning: Sorojchi pills are a Bolivian-made altitude-sickness remedy whose advertising pictures a tourist vomiting at Machu Picchu. Its safety has not been documented, and it contains only pain relievers and caffeine, so we don’t recommend it.
Security has improved dramatically in Cusco. A huge police presence is on the streets, especially around tourist centers such as the Plaza de Armas. Nonetheless, petty crime, such as pickpocketing, is not uncommon: use extra vigilance in crowded markets or when getting on and off buses and trains. Robbers have also targeted late-night and early-morning revelers stumbling back to their hotels. Women should not leave drinks unattended at dance clubs; there have been cases in which beverages have been tampered with.
Tap water is not safe to drink here. Stick with the bottled variety, con gas (carbonated) or sin gas (plain).