AT FIRST glance, the Plaza Mayor might seem like one of Madrid’s tourist traps. English abounds, and advertisements for overpriced sangria and paella hang outside of the many cafes lining the square. Buskers dressed as sailors try to tempt visitors into taking silly photos or buying knick-knacks. But the ostentatious atmosphere belies the square’s importance: this year, Plaza Mayor celebrates 400 years as the beating heart of Spain’s capital. It has persevered through fires, multiple royal dynasties, the civil war, Francisco Franco’s dictatorship and the establishment of democracy. As a part of the festivities “La Plaza Mayor. Retrato y Máscara de Madrid” (“Portrait and Mask of Madrid”), a new exhibition at the History Museum, explores the cultural and political significance of the plaza for Madrileños and for Spain.

Far from remaining an unchanging relic, the exhibit shows how the square has taken on the character of each new era in Spanish history. When Philip II moved the seat of his empire to Madrid in 1561, Plaza Mayor was a town market where farmers and merchants could sell their goods. In 1617 Philip III commissioned a redesign that turned the open-air fair into a place to see and be seen: it was used as a stage for events at the royal court, such as weddings, dances and coronations. It was often turned into a theatre or a bull ring that could seat up to 50,000 people. Entertainment of a darker sort was also hosted there: the plaza became a site of torture and executions during the Inquisition. As Madrid became more multifaceted—transforming from a city that played second fiddle to Toledo into a national capital—so too did its main square.

Plaza Mayor’s look was as transient as its purpose. Almost razed to the ground in 1790, it took six decades to rebuild. A deep rusty orange still dominates the square’s facades today, but Juan de Villanueva’s redesign echoed the neoclassical sympathies of late 18th-century Europe. He closed off the streets running through the plaza, replacing them with arches, and knocked two stories off the buildings. The floor of Plaza Mayor was dug up multiple times over the next 150 years to first turn the square into a glorified garden, then to gut the garden and return the plaza to its “primitive character” and, finally, to build an underground car park. That the square was made and remade every few decades in Spain’s image points to the sheer amount of change Spanish society has experienced. By noting each redesign, the exhibit prompts visitors to view Plaza Mayor as the physical manifestation of whichever dynasty or government was in power at the time.

A large portion of the second half of the exhibit, which shows Plaza Mayor’s metamorphosis from 1843 to 2018, is devoted to the photographs of Martín Santos Yubero. With good reason: Santos Yubero was renowned for his documentary coverage of Madrid, which spanned the better part of the 20th century. Viewed together, his images create a kind of timelapse of the plaza and a microcosm through which to study Spain under Franco. The black-and-white film, emphasising the unforgiving slate of the plaza floor and the gaunt faces of soldiers hunkering between sandbags in the square’s archways, reflect the solemnity and melancholy that seemed to settle over Madrid in the late 1930s. Yearly celebrations for Christmas and the festival of Saint Isidro continued under Franco’s dictatorship, but Santos Yubero’s featured images of these happy occasions showed costumed revelers with glum or serious expressions.

In the decades that followed, the plaza continued to try out new identities, and Santos Yubero was there to document them. The 1960s brought yet another redesign, this time to try to recover the “imperial” character of the Habsburg years. Plaza Mayor again became a vibrant gathering place for locals and tourists, not unlike the party-oriented plaza of the 17th century. One photograph, “La niña tocando la zambomba” (“The girl playing the zambomba”), shows a small child taking part in the plaza’s Christmas celebrations in 1962: the image has more warmth and vitality than any other in the latter half of the exhibit. The small fact of the girl’s joyful smile puts her in stark contrast to the grave faces captured in earlier decades—the modernisation and liberalisation of Spain seemingly evident in Santos Yubero’s choice of subject.

The History Museum does tourists and locals a favour with its detailed account of one of the capital’s main thoroughfares. Just as Madrid has become a centre for government, art, nightlife and football, Plaza Mayor is—all at once—market, park, cafe and stage. Don’t let the pricey drinks fool you: underneath all the gaudiness lie 400 years of la vida Madrileña.

“La Plaza Mayor. Retrato y Máscara de Madrid” is showing at el Museo de Historia de Madrid until November 11th