Argentina
Fourteen colours striped across a mountainside like geological sheet music, visible from a single viewpoint.
The Cerro de los Catorce Colores (Hill of Fourteen Colours) rises at the end of a 25-kilometre dirt road above Humahuaca, and when you reach the viewpoint at 4,350 metres, the claim of fourteen colours — ochre, burgundy, violet, white, green, yellow, orange, pink, and six more that don't have names in common use — reveals itself as an understatement of the geological record. The serrated ridge of Serranía de Hornocal runs for 20 kilometres, each coloured stratum representing a different geological epoch, and the fold pattern pressed into the rock by Andean tectonic forces has created a wavelength visible from 3 kilometres. There are no facilities, no shade, and no sound except the wind.
The Serranía de Hornocal in Jujuy Province is a fold-thrust mountain range formed during the Andean uplift of the Paleogene period, where Precambrian and Mesozoic sedimentary sequences were compressed and tilted to expose their full chromatic range. The fourteen colours identified in the official geological survey correspond to distinct mineral compositions: iron oxides produce reds and yellows, copper produces greens, manganese produces purples, and calcium carbonate produces the white bands. The altitude at the viewpoint — 4,350 metres — means altitude sickness is a genuine consideration, and the 45-minute acclimatisation recommended before beginning the final climb is not advisory but physiological. The drive from Humahuaca through the village of Aparzo passes pre-Inca agricultural terracing still in use for potato cultivation.
Solo
The Hornocal viewpoint on a weekday morning, with the serrated ridge glowing in full sun and nobody within earshot, is one of those moments in high-altitude Argentina that justifies the altitude, the cold, and the difficulty of getting here. The colours are genuinely unlike anything produced by geology elsewhere in the country.
Couple
The early-morning drive up from Humahuaca, reaching the viewpoint at sunrise before the colours flatten in the midday light, requires waking at 5am and leaving immediately — and produces one of the most extraordinary visual experiences in northwest Argentina.
Friends
The Hornocal loop from Tilcara or Humahuaca works well as a group day-trip with a high-clearance vehicle — the dirt road from Aparzo requires it, and arriving as a group at 4,350 metres with the full ridge spread out below makes the effort feel appropriately proportionate.
Provisions from Humahuaca — empanadas and api morado before the drive up to the mirador.
Llama jerky and coca leaves chewed against the altitude on the exposed hillside.

Pedra de Lume
Cape Verde
Float in a salt lake inside an extinct volcano, crater walls rising on every side.

Vale do Paúl
Cape Verde
Sugarcane terraces spill down a volcanic crater into the greenest valley in the archipelago.

Monastery of St. Anthony
Egypt
Earth's oldest inhabited monastery, wedged into a Red Sea mountain canyon since the fourth century.

Hoang Su Phi
Vietnam
Rice terraces so vertiginous they look like topographical maps carved directly into the sky.

Casabindo
Argentina
Argentina's only bull ceremony strips ribbons from horns at 3,400 metres each August.

Parque Nacional Los Alerces
Argentina
Alerce trees 2,600 years old standing in forest unchanged since the last ice age.

Ischigualasto
Argentina
A moonscape where 230-million-year-old dinosaur bones scatter across wind-eroded clay mushrooms and stone cannonballs.

Esteros del Iberá
Argentina
Caiman drift among giant lily pads in a freshwater marsh where time itself pools and stills.