The Salar de Uyuni is so flat that scientists use it to calibrate satellites. Across more than ten thousand square kilometres the surface varies in elevation by less than a metre, which makes it the flattest large surface on earth and a reference target for the radar altimeters that measure sea level from orbit.
It is a salt crust several metres thick over a brine lake, left behind when a prehistoric inland sea evaporated. In the dry season it is a white hexagonal pavement to the horizon with no visible reference points, which is why the perspective photographs work. In the wet season, from roughly December to March, a few centimetres of water sit on top and the whole thing becomes a mirror large enough to see from space.
Underneath it is something in the order of half the world's identified lithium.
La Paz, and the cable cars
La Paz sits in a canyon at around 3,640 metres, with El Alto on the rim above it at over 4,100. That thousand-metre difference used to mean an hour in traffic on switchback roads.
Since 2014 it has meant Mi Teleférico — the largest urban cable car network in the world, ten lines and around thirty kilometres of it, run as ordinary public transport at bus fares. Commuters, schoolchildren and market traders ride it, and a visitor gets the best view of any city in South America for the price of a ticket.
The altitude is not a detail
La Paz is one of the highest cities in the world and Uyuni sits at about 3,650 metres, with tours going over passes above 4,800. Altitude sickness is common and can be serious.
Arrive and do nothing for the first day. Coca tea is offered everywhere and helps a little. Anyone coming from sea level directly into a Uyuni tour should give themselves acclimatisation time first, and anyone with heart or lung conditions should take medical advice before booking.
The five below are grouped by city, and the count is short because the inventory is.
La Paz
The canyon city.
Atix Hotel occupies a building in the Zona Sur with a contemporary Andean design, a serious art collection and the most polished service in Bolivia. It is the best hotel in the country.
Atix Hotel
Zona Sur, La Paz · 5★ · $$$
Contemporary Andean design with a serious art collection
Check availabilityCasa Grande Hotel sits in a converted colonial-style building with suites, a courtyard and a long-standing position among the city's hotels.
Casa Grande Hotel
Zona Sur, La Paz · 4★ · $$
Suites around a courtyard, long established in the city
Check availabilityStannum Boutique Hotel occupies a tower with a rooftop, contemporary rooms and views up the canyon to Illimani.
Stannum Boutique Hotel
Central La Paz · 4★ · $$
A rooftop with views up the canyon to Illimani
Check availabilityUyuni
At the edge of the salt.
Palacio de Sal occupies a building at Colchani constructed largely from blocks of salt — walls, floors, furniture and beds — on the edge of the flat, with the crust starting outside the door.
Palacio de Sal
Colchani, Salar de Uyuni · 4★ · $$$
Built from salt blocks with the crust outside the door
Check availabilityLuna Salada Hotel sits on a rise above the salar, also built from salt blocks, with a spa and rooms facing the flat and the sunset over it.
Luna Salada Hotel
Above the Salar de Uyuni · 4★ · $$$
Salt-built with a spa facing the flat at sunset
Check availabilityWhat we have left off
The tour-operator lodges out on the salar and in the Eduardo Avaroa reserve toward the Chilean border are excluded. Multi-day tours usually include basic accommodation and that is how most people see the lagoons and the geysers. They are hostels rather than hotels.
What to do
Go onto the salar at sunrise and again at sunset. In the wet season the mirror effect is strongest with a low sun; in the dry season the hexagons are sharpest.
Do a multi-day tour if you have the time. The three-day route south crosses coloured lagoons, flamingo colonies, a geyser field at over 4,800 metres and finishes at the Chilean border near San Pedro de Atacama, which makes a neat crossing.
Ride the cable cars in La Paz. The red, yellow and green lines together give the best circuit, and the view from the Línea Roja over the canyon at dusk is the one to time.
See the Witches' Market in La Paz, and the Valle de la Luna outside it, and take the Death Road cycle descent if that appeals — it is commercial now but the drop is real.
Visit the train cemetery outside Uyuni, where nineteenth-century British-built locomotives were abandoned when the mining economy collapsed.
Practical notes
La Paz's El Alto airport is at over 4,000 metres, which means arriving passengers step straight into serious altitude. Uyuni has a small airport with flights from La Paz, or an overnight bus.
May to October is the dry season, best for the hexagon pattern and the southern tour. December to March is the wet season and the mirror, though heavy rain can close parts of the flat.
Nights on the altiplano are extremely cold in any season.
Every hotel bookable in Bolivia
Why is the salt flat used to calibrate satellites?
Across ten thousand square kilometres the elevation varies by under a metre, which makes it the flattest large surface available.
When is the mirror?
Roughly December to March, when a thin layer of water sits on the crust. The dry season gives the hexagon pattern instead.
How serious is the altitude?
La Paz is around 3,640 metres and tours go above 4,800. Take a day to acclimatise and seek advice if you have heart or lung conditions.
How many nights?
Five. Two in La Paz to acclimatise and three for Uyuni and the southern route.