At 7,628 feet above sea level in southern Peru, Arequipa sits in a valley ringed by three volcanoes: the still-active Misti, Chachani and Pichu Pichu.
Its historic center, named a UNESCO World Heritage Site in 2000, is built largely of sillar, a volcanic stone formed by eruptions whose pyroclastic flows blanketed the Chili River basin thousands of years ago.
That white, porous ignimbrite, cut from the Añashuayco quarries, earned the city its longtime nickname: “the White City.”
The stone gave Arequipa more than its color. It proved resilient against the earthquakes that have shaken the region since the Spanish founded the city in 1540, and it’s the reason the city’s Andean baroque architecture is still standing.
Today Arequipa is one of southern Peru’s leading destinations, a city made for wandering, within reach of natural wonders like the Colca Canyon, which is worth the trip on its own. Watched over by its volcanoes, the White City is yet another reason to visit Peru.
Misti and Chachani: The Volcanoes That Shaped Arequipa
The symmetrical cone of Misti dominates Arequipa’s skyline. The summit of the 19,101-foot stratovolcano lies 10.6 miles from the city center.
The Geophysical Institute of Peru monitors it around the clock because of the risk it poses to the more than 1 million people living in its shadow.
Eruptions recorded since Inca times in the 15th century have made the volcano a constant threat, but they also left behind ash that enriched the surrounding farmland and encouraged farmers to build terraces that trapped the valley’s moisture.
Beside Misti rises the Chachani massif, which reaches 19,872 feet. Despite its height, its gentle slopes make it one of the most popular 6,000-meter peaks for high-altitude expeditions in South America.
During the Pleistocene, successive eruptions and pyroclastic flows from this volcanic complex laid down the densest layers of ignimbrite, which are quarried today from open pits in the Añashuayco and Seco ravines.
The porous stone from its slopes insulates against the sharp temperature swings of the Andean desert, keeping the interiors of buildings cool during the day and warm at night.
In a desert landscape with little timber, colonial builders turned to these volcanic deposits after the earthquakes of 1582 and 1600 brought down traditional adobe buildings.
Because sillar from the slopes of Chachani and Misti is so easily carved, builders could raise walls up to 5 feet thick and build barrel vaults able to withstand the earthquakes caused by the subduction of the Nazca Plate. Meltwater from these same peaks also feeds the aquifers that sustain the Chili River, ensuring a steady water supply in an arid region.
Sillar Architecture: From Convents to the Plaza de Armas
Sillar was never limited to private homes. It also defined the religious and civic monuments built between the 16th and 19th centuries.
The Basilica Cathedral of Arequipa fills an entire side of the Plaza de Armas, its facade lined with 70 columns carved from white ignimbrite and framed by two towers rebuilt after the 2001 earthquake.
A short walk from the plaza stands the Monastery of Santa Catalina de Siena, a cloistered city within the city, founded in 1579 and covering 215,000 square feet. The complex unfolds like an urban labyrinth: narrow cobblestone lanes, walls washed in cobalt blue and rust red, and the cells where hundreds of Dominican nuns lived in strict seclusion for nearly four centuries.
Among the stately mansions of the old town, the Casa del Moral, built in the late 18th century, stands out. Named for the century-old mulberry tree in its main courtyard, it is one of the finest examples of secular sillar architecture. Its doorway bears a baroque stone relief in which Spanish coats of arms share space with Andean pumas and local plant motifs.
The Museo Santuarios Andinos holds the body of Juanita, known as the Ice Maiden or the Lady of Ampato. Sacrificed in a ritual around 1450, the 14-year-old Inca girl was found frozen in 1995 near the summit of Ampato volcano, at more than 20,600 feet, along with her textile and ceramic offerings.
Working Quarries and the Gateway to the Colca Canyon
The craft of master stonecutters endures on the edge of the city. In the Añashuayco ravines, workers quarry the ignimbrite blocks still used to restore colonial buildings and shape them by hand with sledgehammers, keeping alive a trade handed down through generations.
Arequipa is also the overland gateway to the Colca Canyon, one of the deepest gorges on Earth, plunging more than 11,150 feet from its rim to the riverbed.
From its overlooks, visitors can watch Andean condors (Vultur gryphus) ride the canyon’s rising thermals and glide above the valley. The canyon is home to one of the species’ most stable populations.
The Balance Between Magma and Stone
Arequipa owes its existence to an uneasy truce with the restless geology of the Peruvian Andes. The same volcanoes that remain a latent threat also supplied the stone for its arches, vaults and facades.
Every street corner is a reminder that the people of the Andes learned to live on this land by shaping the desert’s volcanic ash into a city of pale stone at the foot of the mountains.
