ISABEL RUBIO ARROYO | Tungsteno

The world's most extreme roads are routes where engineering and risk go hand in hand. The Yungas Road in Bolivia, with its narrow stretches skirting sheer drop-offs, is among the best known for its extreme danger. China’s Tianmen Mountain Road climbs a mountainside via 99 hairpin bends carved directly into the rock. In the Indian Himalayas, high-altitude passes such as Khardung La, at over 5,300 metres, force drivers to contend with ice, fog, and landslides. In Canada, ice roads exist only in winter, crossing frozen lakes and endless tundra. In this article, we investigate which roads truly deserve the title of the world's most extreme.

“The Road of Death”

The North Yungas Road, known as the Road of Death, links La Paz in Bolivia with the subtropical Yungas valleys and the Amazon region. At just 64 km long and with a descent of 3,500 metres, the road has gained global notoriety due to its extreme danger. The highway is narrow, with sections barely three metres wide, and features tight bends, blind turns, and almost no guardrails. Drivers must contend with sheer drop-offs ranging from 400 to 1,000 metres, as well as dense fog, mud, and waterfalls that render the surface treacherously slippery. Some media outlets estimate that this road used to claim between 200 and 300 lives per year. Despite the risks, the road attracts some 25,000 visitors each year, including cyclists and motorcyclists, who willingly brave the potholes, traffic, and constant threat posed by the surrounding cliffs.

The North Yungas Road challenges drivers and cyclists with its narrow stretches. Credit: World Travel Guide

An “Avenue to the Heavens”

Tianmen Shan Big Gate Road, also known as the Avenue to the Heavens or the Road of 99 Curves, is located in Tianmen Mountain National Park in Hunan, China. This 11-kilometre route climbs from the foot of the mountain to Cave Square, reaching an altitude of around 1,100 metres. Due to its extremely tight hairpin turns, narrow sections running alongside precipices, and frequent fog, it is considered one of the most dangerous roads in the world. Given its proximity to the abyss and minimal margin for error, the route is only suitable for experienced drivers.

In recent years, however, it has also become a popular tourist destination and venue for cycling competitions and mountain races. Its dramatic landscape inspired James Cameron when designing the floating mountains in the Avatar films.

Tianmen Shan Big Gate in Zhangjiajie, China, is known as the Avenue to the Heavens. Credit: Travel and Home

One of the world’s most dangerous mountain passes

Khardung La, located in the Ladakh region of India, is one of the world’s most famous and challenging mountain passes. Rising to 5,359 metres (17,582 feet) above sea level, its extreme altitude exposes travellers to Acute Mountain Sickness (AMS). The road itself is narrow and slippery in places, with several sections in poor condition. Heavy traffic and military convoys can cause delays and increase the risk of accidents on the single lane sections. The pass is also subject to bad weather and geological hazards, such as avalanches, rockfalls, and heavy snowfall, and remains closed for several months each year. The remoteness of the area and poor logistics make the journey even more challenging.

There is no medical assistance available along the entire route, and facilities at the summit are extremely limited. In addition, its proximity to the borders with Pakistan and China results in a heavy military presence, and some travellers require a special permit to cross the pass.

There is usually a military presence at Khardung La. Credit: Vyacheslav Argenberg / Creative Commons.

A road built on ice

The Tibbitt to Contwoyto Winter Road, located in Canada’s Northwest Territories and Nunavut, is the longest heavy-haul ice road in the world. Spanning between 400 and 600 kilometres, it links Tibbitt Lake, near Yellowknife, with diamond mines such as Ekati, Diavik, and Gahcho Kué. It is a seasonal route, rebuilt every year starting in December, and is typically open from February to late March. Around 85% of the road runs over frozen lakes, while the remaining 15% crosses short stretches of permafrost peatland.

Despite being one of the best-managed and safest roads in North America due to strict monitoring and controls, it is still considered dangerous for several reasons. The ice must reach a minimum thickness of 74 centimetres for the road to open and 100 centimetres to support fully loaded trucks. Speed limits for loaded vehicles are restricted to 25 kilometres per hour. Drivers may encounter snowstorms, strong winds and near-zero visibility, and the journey itself can take between 14 and 18 hours in complete isolation. One of the greatest threats to this ice road is climate change, which can shorten the operating season or weaken the ice.

The Tibbitt to Contwoyto Winter Road depends entirely on the thickness of the ice. Credit: Steven TenHave

Tungsteno es un laboratorio periodístico que explora la esencia de la innovación.

ISABEL RUBIO ARROYO | Tungsteno

Many modern cities conceal beneath their streets a vast network of secret tunnels that serve various purposes, ranging from former shelters and military command centres to historic ossuaries. Cities like Berlin, London, Paris, and New York reveal that urban life and history extend beyond the surface. Their depths hold a captivating heritage of wartime bunkers, espionage routes, and abandoned infrastructure.

Berlin

Berlin's tunnels have historically served as strategic refuges and military command centres, preserving stories from the Second World War through the Cold War. Several associations are dedicated to exploring and documenting these underground spaces, offering guided access to iconic air-raid shelters and bunkers. Their aim is to show how the city prepared for conflict and how these structures protected its inhabitants during times of crisis.

Beyond shelters, escape tunnels tell stories of ingenuity and resistance. More than 70 tunnels were built beneath the Berlin Wall, enabling some 300 people to flee from East to West. The city’s subterranean past also hides other disused infrastructure, such as abandoned railway tunnels and even former brewery warehouses.

During the Cold War, some tunnels were used as escape routes. Credit: DW Euromaxx

London

The Kingsway Exchange tunnels complex, which stretches across 8,000 square metres beneath High Holborn, was built during the Second World War to protect Londoners during the Blitz. Although it was never used for that purpose, the site hosted the Special Operations Executive (SOE), Winston Churchill's wartime espionage organisation. James Bond author Ian Fleming worked regularly with the SOE in this labyrinth of tunnels, which may have inspired Q Branch in his famous novels.

The tunnels remained strategically important after the war. During the Cold War, they functioned as a strategic communications hub. Following the Cuban missile crisis in 1962, the complex served as a relay point for the famous “red telephone” hotline between the Pentagon and the Kremlin. A government bunker was also built for use in the event of a nuclear attack. Today, there are plans to open the site to the public as a tourist attraction, featuring a military intelligence museum, an exhibition on espionage, and a bar marketed as “the deepest bar in the world in a city.”

The passages that protected London during the Second World War.

Paris

Much of the Parisian subsoil consists of nearly 200 miles (about 320 kilometres) of limestone quarries, originally excavated to build the city. Part of this network forms the Paris Catacombs, one of the largest ossuaries in the world. They contain the remains of some six million Parisians and have been dubbed "the empire of death." These abandoned quarries are sometimes visited illegally by "urban explorers," who have been known to organise secret underground nightclubs and cinemas.

Paris also boasts a complex sewer system spanning 1,662 miles (around 2,675 kilometres), modernised in the 19th century and historically used as escape routes for criminals. The metro network also includes four “ghost” stations closed since the Second World War. Other underground points of interest include a secret military bunker near the Eiffel Tower and the basement of the Opéra Garnier, which houses a real underground lake.

The catacombs of Paris lie 20 metres underground, with 243 steps and 2,000 metres of tunnels. Credit: Paris Musées

New York

In 2024, an illegal tunnel was discovered in Brooklyn, New York, beneath the Chabad-Lubavitch headquarters in Crown Heights, a busy Jewish site that welcomes thousands of visitors a year. The 60-foot (18-metre) tunnel was dug clandestinely and without structural reinforcements, causing destabilisation under the synagogue sanctuary. Due to safety concerns, New York City issued an emergency order to stabilise the building.

Illegal tunnel discovered beneath an historic synagogue in Brooklyn, New York. Credit: Eyewitness News ABC7NY

The evidence suggests the tunnel was constructed by a group of students known as the Tzfatim, who sought to expand the synagogue in accordance with the vision of their deceased leader, Rabbi Menachem Mendel Schneerson. When police arrived to inspect the tunnel, clashes broke out with members of the community. The altercation resulted in nine arrests on charges including criminal damage, reckless endangerment, and obstruction of government administration.

Tungsten is a journalistic laboratory that explores the essence of innovation.