Inside Qeshm, Iran’s underground missile fortress and geological wonder US-Israel war on Iran

Beneath the labyrinthine salt caves and emerald mangrove forests of Qeshm Island in the Strait of Hormuz, a different kind of architecture is buried.

While tourists once flocked to this “open-air geological museum” to catch a glimpse of its surreal rock formations, the world’s gaze is now fixated on what lies beneath the coral: Iran’s “underground missile cities.”

As the US-Israeli war erupts over Iran, Qeshm has transitioned from a free-trade and tourist haven to a front-line fortress – and the ultimate strategic prize for US navies currently deployed in the strait.

Its sheer size – roughly 1,445 sq km (558 sq mi) – allows it to physically dominate the entrance to the strait from the Gulf, acting as a cork in the world’s most important energy transit route.

These days, the island’s 148,000 residents — primarily Sunni Muslims who speak the distinctive Bandari dialect — live at the intersection of this pristine natural beauty and modern military tensions. Their lives are still dictated by the sea, which is celebrated every year during Nowruz Sayyadi, the fishermen’s new year, when all fishing stops to honor the sea’s bounty.

But on March 7 – a week into the war – US airstrikes targeted a critical desalination plant on the island. The strike, which Tehran branded a “heinous crime” against civilians, cut off fresh water supplies to 30 surrounding villages.

In a swift retaliatory move, the Islamic Revolutionary Guard Corps (IRGC) launched a strike against US forces at the Zufair base in Bahrain, accusing the neighboring Gulf state of launching an attack on Queshm.

Here’s what we know about the island’s strategic importance and history.

‘Missile cities’ – a fortress on a strait

Today, the island’s modern industrial facade, bolstered by its status as a free-trade-industrial zone since 1989, is overshadowed by Iran’s role as an “unsinkable aircraft carrier”.

Just 22km (14 miles) south of the port city of Bandar Abbas, Qeshm dominates the Strait of Clarence, also known as Kuran, and serves as a primary staging ground for Iran’s “asymmetric” naval power, analysts say.

Although exact figures regarding the number of Iranian fast attack boats and coastal batteries hidden within the island’s underground labyrinth remain highly classified, their strategic purpose is clear. Retired Lebanese Brigadier-General Hassan Jouni, a military and strategic expert, told Al Jazeera that Qeshm contained “hitting Iranian capabilities” inside what he described as an underground “missile city”. These vast networks are designed for one primary purpose, Jouni said: to effectively control or close the Strait of Hormuz.

He has successfully done this. Shipping through the strait was effectively halted last week when Iran threatened to attack ships trying to pass through.

Now, only a few vessels carrying vital oil and gas supplies to the rest of the world are allowed in, as countries scramble to strike deals with Iran for their own tankers and the administration of United States President Donald Trump tries to assemble a fleet of warships to force open the waterway.

As Queshm becomes the focus of a 21st-century power struggle, its silent salt caves and ancient temples serve as reminders that past empires and military confederations such as the Portuguese and British have finally faded away, a geographical fortress on the strait situated on the tumultuous tides of history.

An island of many names

The identity of Qeshm, known in Arabic as Jajira-al-Tawila (Long Island), was forged by a succession of kingdoms.

According to the Encyclopedia Iranica, the Greek explorer Nearchus referred to it as Oracta and saw the legendary tomb of Erythras, the name of the Erythraean sea. By the ninth century, Islamic geographers were calling it Abarkawan, the name later deriving its folk-etymology as Jajira-ye Gawan, or “island of the cow”.

Considering the island’s strategic importance, the rulers of Hormuz moved their entire court there in 1301 to escape Tartar attacks. For centuries, it served as the region’s “water barrel”, providing vital drinking water to the arid kingdom of Hormuz on the eastern side of the Gulf.

The island’s riches were so legendary that in 1552, the Ottoman commander Piri Reis raided it for what contemporary accounts described as “the richest prize ever found in the world”.

The island’s colonial history is equally turbulent.

The Portuguese built a massive stone fort at Queshm in 1621. And a year later, a combined Persian and English force drove the Portuguese out of that fort, costing the life of Britain’s famous Arctic navigator William Baffin.

By the 19th century, the British established a naval base at Basidu (Bassadore), which remained the headquarters of the British Indian Navy until 1863. The British coaling station was finally abandoned until 1935 at the request of Reza Shah Pahlavi, then-Shah of Iran.

A museum under fire

Beyond the military watchtowers and underground silos of the IRGC, Qeshm is one of the most ecologically diverse places in the Middle East. It is home to the Hara Mangrove Forest, an important breeding ground for migratory birds, and the Queshm Geopark – the first in the region to be recognized by UNESCO, an honor it earned in 2006.

The landscape of the island includes:

• Valley of the Stars: A complex network of canyons and rock pillars carved by millennia of erosion. Local legends say that the valley was formed by a falling star that shattered the earth.

• Namakdan Salt Cave: One of the longest salt caves in the world, it stretches over 6km (3.7 miles). Its crystalline formations are hundreds of millions of years old, containing some of the purest salt in the bay.
• Chakooh Valley: A deep, narrow corridor of limestone and salt, where vertical walls create a natural cathedral of stone.