Tehran

Tehran unfolds across the southern slopes of the Alborz range, a city of dizzying contrasts where ancient stones lie beside glass-and–steel towers. At 1,200 meters above sea level, its flat southern districts press against the central desert, while to the north, hills climb toward peaks that exceed 2,000 meters. By 2025, nearly 9.8 million people will call its municipal boundaries home, and with more than 16.8 million in the wider metropolitan area, Tehran ranks as the most populous city in Western Asia and the second‑largest metropolitan zone in the Middle East after Cairo. Through its layers of history and its fractured topography, the Iranian capital reveals both its endurance and the frictions that accompany rapid growth.

Long before it hosted Iran’s government, the ground beneath Tehran belonged to Rhages, known in antiquity as a major Median settlement. Situated a few kilometres south of today’s city center, Ray (as it is still called) witnessed the rise and fall of empires. Its walls were breached by Arab, Turkic, and Mongol invaders, and only fragments remain amid the suburban sprawl. Over centuries, Ray was absorbed into Greater Tehran, its ruins serving as silent witnesses to the city’s relentless expansion and transformation.

In 1786, Agha Mohammad Khan of the Qajar dynasty declared Tehran Iran’s capital. He sought a seat of power more secure than the traditional dynastic centers, close enough to the Caucasus—then contested in the Russo‑Iranian Wars—yet sheltered from factional rivalries. That decision inaugurated an era of construction: modest palaces, military barracks and the foundation of what would become the sprawling bureaucratic machine of a modern state. Even amid the Qajar decline, Tehran’s profile rose steadily, its population doubling under Fath‑Ali Shah. By the turn of the nineteenth century, new streets and public squares took shape, the most prominent being Toopkhaneh (now Imam Khomeini Square). Mosques in the city core took on fresh ornament as urban services and civic institutions edged out the old gates and caravanserais.

The twentieth century was a period of profound change. Reza Shah Pahlavi embarked on large‑scale building projects in the 1920s, introducing European‑inspired boulevards and the foundations of a modern infrastructure. Mehrabad Airport opened its runways, and rail lines crisscrossed the plain. As the Pahlavi state modernized schools, ministries and cultural venues, Tehran drew migrants from every province. Between the 2006 and 2016 censuses, the city population rose from 7,711,230 in 2,286,787 households to 8,693,706 in 2,911,065 households. By 2025, roughly 9.8 million residents will live within its official limits. This surge reshaped Tehran’s social fabric: in a 2010 University of Tehran survey, 63 percent of those interviewed had been born in the city, 75 percent identified as ethnic Persian, and nearly 98 percent were fluent in Persian, with 13 percent also speaking a European language.

Tehran’s municipal area is divided into 22 districts. Twenty lie within Tehran County’s Central District; districts 1 and 20 extend into Shemiranat and Ray counties. Southern districts—home to the railway station at 1,117 meters above sea level—are flatter and more densely built, while northern neighbourhoods rise along the slopes. Valiasr Street, the city’s spine, stretches 17.3 kilometres from south to the Tajrish Square at 1,712.6 meters. Beyond, Velenjak climbs to nearly 2,000 meters.

Wealth and modernity concentrate in the north: enclaves such as Zafaraniyeh, Jordan, Elahiyeh and Niavaran are known for embassies, high‑rise apartments and leafy parks. In contrast, central Tehran hosts ministries, ministries and commercial headquarters, while the south remains more affordable but densely populated.

Tehran’s climate straddles the line between cold semi‑arid (BSk) and hot semi‑arid (BSh). Summers are hot and dry, often topping 38 °C in July; winters bring cool, rainy days. The Alborz mountains shape local breezes: at night, the “Tochal breeze” flows down from the peaks as they cool, offering relief to upper‑city residents. In summer, winds from the southern deserts can raise temperatures, while westerly planetary currents bring dust and occasional rain. The northern hills, with their gardens and green corridors, typically run two to three degrees Celsius cooler than the concrete‑choked south.

While ethnic Persians form the majority—about 75 percent self‑identified in 2010—Iranian Azeris compose the second largest group at roughly 10–15 percent, followed by Mazanderanis at 5 percent. Smaller communities of Kurds, Armenians, Georgians, Bakhtyaris, Talysh, Baloch, Assyrians, Arabs, Jews and Circassians add further strands to the city’s tapestry, though most have assimilated linguistically into the dominant Tehrani dialect of Persian. After the 1979 Revolution, many Tehranis emigrated—particularly to the United States, Germany, Sweden and Canada—leaving both gaps in certain professional circles and brisk remittance flows.

Twelver Shia Islam is the state religion and the faith of the majority. Sunni Muslims and adherents of Sufi orders coexist alongside Christian denominations, Jews, Zoroastrians and a small Baha’i minority. A modest Sikh community maintains a gurdwara, visited by Indian Prime Minister Manmohan Singh in 2012. In a 2016 “Tehran Survey,” 53.5 percent of respondents rated religion as “very important,” 31.1 percent as “rather important,” 10.5 percent “not very important,” and 4.8 percent “not at all important.”

Tehran’s royal heritage is visible in its palaces. Golestan Palace, a Qajar complex of mirrored halls and marble terraces, sits in the old city core. To the north, Sa’dabad and Niavaran palaces, once summer residences for the Pahlavi dynasty, perch in wooded grounds. The marble‑clad Marmar Palace showcases European furnishings and sweeping views. Together, these sites chart a journey from 18th‑century regality to mid‑20th‑century modernism.

Tehran’s museum scene spans epochs and media. The National Museum houses archaeological finds from the Medes to the Sassanids. Nearby, the Carpet Museum displays masterpieces of Persian weaving, while the Abgineh Museum focuses on glass‑and‑ceramic art. The Cinema Museum, set in Ferdows Garden, celebrates Iranian film history. The Museum of Contemporary Art boasts the country’s finest modern collection—Van Gogh, Picasso and Warhol rub shoulders with pioneering Iranian artists. The National Jewelry Museum safeguards one of the world’s largest crown‑jewel collections.

Each spring, Tehran’s International Book Fair draws publishers, scholars and readers to the Shahr Aftab exhibition halls. Trade shows and festivals occur year‑round, from auto expos to craft fairs, showcasing both heritage and emerging creativity.

More than 2,100 parks dot the metropolis, covering over 12,600 hectares—20 percent of Tehran’s area. Jamshidie Park, once a Qajar prince’s estate, became a public grove under Empress Farah Pahlavi. The Birds Garden, Iran’s largest aviary, hosts dozens of species, while the city zoo shelters some 290 vertebrates. Ab‑o‑Atash Park (“Water and Fire”) delights children with fountains and fire towers framed by an outdoor amphitheater.

As Iran’s economic heart, Tehran employs 30 percent of the public sector workforce and nearly half of the country’s major industrial firms. Factories produce automobiles, electronics, textiles, sugar, cement and chemicals; carpet and furniture showrooms line the commercial districts. Oil refineries—Pars, Speedy and Behran—operate within city limits. Though sanctions limit many foreign firms, the Tehran Stock Exchange remains a leading performer among global exchanges, reflecting both volatility and opportunity.

Despite official plans to relocate the capital—driven by seismic risk and air pollution—Tehran remains stubbornly central. Its arterial highways were built for 300,000 vehicles; today, over five million cars clog the streets. Buses have run since the 1920s, and the Bus Rapid Transit system, inaugurated in 2008, now carries 1.8 million passengers daily along ten lines and 215 stations. Trolleybuses, first introduced in 1992, were mothballed around 2013 but revived in 2016 on a single 1.8‑kilometre route with refurbished Škoda vehicles.

Tehran Metro’s first two lines opened in 2001; by 2025, eight lines will thread beneath the city, linking suburbs to the core. Aboveground, over 200,000 taxis ply every neighbourhood, with airport taxis commanding higher fares. Mehrabad Airport handles domestic and charter flights; Imam Khomeini International, 50 kilometres south, is the gateway for global air traffic. The central railway station dispatches trains nationwide and connects to Europe via the legendary Tehran–Europe express.

Air quality has long been a vexing problem. Geographic bowl‑like topography, rapid motorization and industrial emissions conspire to trap smog, prompting talk of moving the government seat elsewhere. Yet the city’s resilience is clear: new green belts, stricter building codes and expanded public transit seek to ease congestion and pollution.

Earthquakes pose another hazard. Despite frequent tremors, no major quake has struck Tehran since 1830. Modern high‑rise construction now includes reinforced frameworks and seismic dampers; still, the juxtaposition of century‑old structures and soaring towers underscores both the city’s ambition and its vulnerability.

Tehran resists simple characterizations. It can feel overwhelming—horns honk in snarled traffic, and skyward towers can block the mountain breeze—but pockets of calm endure. In leafy alleyways, fountains murmur beneath plane trees; in northern cafes, students debate the future; in historic mosques, the polished marble gleams under stained‑glass windows. Festivals old and new—Nowruz, Chaharshanbe Suri, Yaldā, even Halloween—bring neighbourhoods together in remembrance and revelry.

Far from a monolithic capital, Tehran is a mosaic of memories and aspirations. Its streets bear the footprints of conquerors and revolutionaries, poets and engineers. Here, every stone and spire tells a story of endurance, adaptation and the ceaseless hum of life. In its contradictions—ancient and modern, green and grey, crowded and serene—Tehran reveals both its burdens and its enduring pulse.