Mount Roraima

Very, very long ago, sand piled up in thick layers and turned into hard rock.

This hard rock wears away only very slowly. That is why the mountain stays tall, with a flat top and steep sides.

Roraima is made of sandstone, rock formed from layers of sand pressed and cemented together. Geologists who dated tiny crystals in rock layers within these sandstones found them to be about 1.9 billion years old.

The highest parts of the Guiana Highlands are flat-topped plateaus capped with sandstone that resists erosion, Britannica explains. Because this tough cap rock wears away so slowly, tepuis like Roraima stand high above the lower land around them, with steep cliffs on their sides.

The sandstones of Roraima belong to the Roraima Supergroup. Santos and colleagues (Geological Society of America Bulletin, 2003) dated zircons from volcanic tuffs within the supergroup to 1,873 ± 3 million years (Paleoproterozoic, Orosirian) and set a minimum age of 1,782 ± 3 million years from mafic sills that cut it. They interpret the supergroup as the fill of a foreland basin of about 1,200,000 km², fed by sediment from the Trans-Amazon mountain belt, and show that some Roraima-like outliers are younger and belong to separate units.

Britannica describes the highest landforms of the Guiana Highlands as tabular plateaus capped with resistant sandstone. Above a rolling basement upland mostly below 300 m, these resistant caps form the highest ground in the region, and Roraima's vertical sandstone walls rise high above the hills of the Gran Sabana.

The top of Roraima is cut off by high cliffs, like an island in the sky.

Special plants grow there. Some are pitcher plants. They catch tiny insects in little cups full of water!

Because Roraima's summit is surrounded by cliffs, its plants and animals are cut off from the lowlands below. When explorers first reached the top in 1884, they sent plant specimens back to Kew in England, and scientists there identified more than 50 species new to science, such as a shrub named Bonnetia roraimae.

The tepuis are home to marsh pitcher plants called Heliamphora. These carnivorous plants catch insects in cone-shaped pitchers. Kew says the first one known to science was spotted on the slopes of Mount Roraima in 1838, and that all of the roughly 18 species are found only in Venezuela, Guyana and Brazil.

Kew records that specimens from the 1884 expedition yielded more than 50 species new to science, among them Bonnetia roraimae. The marsh pitcher plants, Heliamphora, are emblematic of the tepuis: about 18 species, all endemic to Venezuela, Guyana and Brazil. The first, H. nutans, was found by Robert and Richard Schomburgk on Roraima's slopes in 1838 and described by George Bentham at Kew in 1840; it grows at 1,200–2,800 m on the tepuis of the Guiana Shield. Its genus name comes from Greek words for marsh and jar.

The surrounding region is very wet: Britannica notes abundant rainfall with no really dry season, mostly tropical rainforest with savanna in parts of southern Venezuela and Guyana. The photo here shows grassy hills and patches of forest below the cliffs.

For a long time, nobody could find a way to the top.

In 1884, a team of explorers finally climbed up. They brought back plants no scientist had seen before.

For years, people wondered what was on top of Roraima. In 1877 a British magazine asked whether anyone would explore it. Kew's director, Sir Joseph Hooker, supported an expedition, and in 1884 a team led by Everard im Thurn became the first to reach the summit.

Stories of these expeditions are thought to have inspired the writer Arthur Conan Doyle's adventure novel The Lost World (1912), about a high plateau where prehistoric animals had survived. The photo on this page was taken from the road from Paraitepuy, a community of the Pemón people in Venezuela.

Kew's account traces Victorian fascination with the unclimbed tepui: in April 1877 The Spectator asked whether anyone would explore Roraima, and Kew's director Sir Joseph Hooker supported an expedition. In 1884 Everard im Thurn, magistrate in Pomeroon, led the first team to reach the summit, opening the way for further scientific exploration; he later became Governor of Ceylon and President of the Royal Anthropological Institute.

Kew notes that reports from early Victorian expeditions to Roraima are thought to have inspired Arthur Conan Doyle's The Lost World (1912). The hero photo's record places the viewpoint on the road from Paraitepuy, a Pemón community in the Gran Sabana of Venezuela. On the Brazilian side, Monte Roraima National Park is administered by ICMBio.

Roraima is far from towns, and it rains a lot.

Its special plants grow almost nowhere else. Never pick them. Leave everything just as you find it.

Roraima is remote, and the Guiana Highlands get plenty of rain, with no really dry season, Britannica says. Its cliffs are high and sheer, so any trip there takes careful planning.

Many of the plants on the tepuis grow nowhere else, so stay on established routes, never pick plants and never take rocks home. On the Brazilian side the mountain is part of Monte Roraima National Park, so follow the rules of the protected area you visit.

Roraima's remoteness, sheer cliffs and very wet climate (abundant rainfall with no truly dry season, according to Britannica) make any visit a serious undertaking. Visitors should check the current rules of the relevant protected area; in Brazil the mountain lies in Monte Roraima National Park, administered by ICMBio.

The summit's isolated flora, including endemic pitcher plants and species first described from Roraima, is fragile. Staying on established routes, removing nothing and leaving no waste are the main ways visitors can avoid harming a landscape that has stood apart for so long.