Altitude, Money, Safety and eSIM in Peru
Altitude sickness (soroche) is a genuinely real risk in Cusco (11,152 ft/3,399 m), Lake Titicaca (12,507 ft/3,812 m), and on treks — plan 2-3 acclimatization days, hydrate heavily, and skip alcohol on day one. Currency is the Peruvian sol (PEN, S/); carry cash for markets and small towns, cards work in cities. Peru's safety picture is generally good in tourist zones with normal precautions against petty theft, not violent crime.
This is the section that quietly makes or breaks a Peru trip, and here altitude genuinely deserves top billing — it affects more travelers, more predictably, than anything else on this page. Also covered: cash versus cards, a balanced safety read, and getting online.
Altitude sickness (soroche) — the real playbook
Cusco sits at 11,152 ft (3,399 m) and Lake Titicaca at 12,507 ft (3,812 m) — both high enough to cause real symptoms (headache, nausea, dizziness, breathlessness, poor sleep) in otherwise healthy travelers, especially those flying in directly from sea level. It's not about fitness level; even very fit people get hit hard, and it's genuinely unpredictable who's affected worse.
The practical playbook: build in 2-3 acclimatization days in Cusco before any serious trekking or Rainbow Mountain; consider spending your first night or two in the lower-altitude Sacred Valley instead of Cusco itself; drink far more water than feels necessary; skip alcohol and heavy exercise for your first 24-48 hours; and try coca tea (mate de coca), a widely used local remedy that genuinely helps with mild symptoms for many people. Some travelers also ask their doctor about acetazolamide (Diamox) before the trip as a preventive measure — discuss it with a doctor who knows your health history, not a generic online recommendation.
If symptoms are severe (intense headache unrelieved by rest and hydration, confusion, or serious breathlessness at rest), that's a sign to descend and seek medical attention rather than push through — most hotels and clinics in Cusco can provide supplemental oxygen, and it's a normal, common request there, not an overreaction.
Money and ATMs
The Peruvian sol (PEN, S/) is the currency everywhere. Check a live exchange rate before your trip since it moves — as a rough planning anchor, $1 has recently traded around S/3.7-3.8. Cards are widely accepted in Lima and Cusco's hotels, restaurants, and larger shops, but cash is still essential for markets, small towns, local transport, and tips.
| Payment method | Where it works best |
|---|---|
| Cash (soles) | Markets, street food, small towns, local transport, tips |
| Credit/debit card | Hotels, restaurants, larger shops in Lima and Cusco |
| USD cash | Accepted informally in some tourist businesses, but soles are safer to rely on |
Is Peru safe? A balanced answer
Peru's main tourist circuit — Lima's Miraflores/Barranco/San Isidro, Cusco's historic center, the Sacred Valley, and Machu Picchu itself — sees heavy tourism and is generally considered safe with normal big-destination precautions. The realistic risks are petty theft (phone-snatching, bag-slashing in crowded markets or buses) and opportunistic scams, not violent crime aimed at tourists. As with most of Latin America, some areas outside the standard tourist routes see more serious issues largely unconnected to travel — check your government's current advisory before venturing off the beaten path.
The lower-stakes stuff worth knowing: don't hail unmarked taxis off the street in Lima (use Uber/Cabify instead), keep bags zipped and in front of you in crowded markets, and stick to registered tour operators for treks and Amazon lodges rather than unusually cheap unlicensed operators.
eSIM and staying connected
eSIM works well in cities and along the main tourist circuit — providers like Airalo and Holafly sell data plans from around $6-18 for 7-15 days, active before you land. A physical local SIM (Claro or Movistar, sold at the airport or in any city) costs roughly $8-15 for two weeks of solid coverage; note that signal genuinely thins out in remote Amazon and high-Andes areas regardless of provider.
Water and food safety basics
- Don't drink tap water directly — bottled or purified water is cheap and available everywhere, including small shops in even remote towns.
- Ice at established restaurants in Lima and Cusco is normally fine; be a bit more cautious at very informal roadside stalls.
- See our food guide for how to eat ceviche and street food safely without missing the best part of the trip.