At two in the afternoon on the last day of July 2024, a Greenpeace technician points a thermographic camera at the granite of the Plaza Mayor and the screen returns a number close to sixty-three degrees. A few hundred metres east, in the Puerta del Sol — the symbolic centre not just of Madrid but, by the brass plaque set into its paving, of all Spain — the same camera reads in the mid-fifties. The air temperature that day is high but survivable. The ground is not. This is the gap that the campaigners want photographed: not what the thermometer says, but what the stone does with the sun once the trees are gone.
The Puerta del Sol they are standing on is barely a year old. It re-opened in the spring of 2023 after a remodelling that produced, by the city’s own measurements, roughly twelve thousand square metres of pale granite and, famously, not a single tree. Madrileños named it almost immediately: la sartén, “the frying pan”. The story of how the most-photographed square in the country became a cautionary tale — and what the city is now spending to undo the heat it built — is the story of a municipal government caught between a hard mineral instinct and a green-cooling ambition it also, genuinely, holds.
The square that could not be planted
It is worth correcting one tempting version of events at the outset. There was no dramatic recantation, no mayor walking back a masterplan in a single repentant press conference. The mayor of Madrid since 2019, re-elected in 2023, is José Luis Martínez-Almeida of the Partido Popular, and his administration has defended the Sol redesign throughout. What happened was slower and more bureaucratic than a confession, and in some ways more revealing: the city argued, repeatedly, that it could not green the square even if it wanted to.
The reasoning runs through two locked doors. The first is heritage. The Puerta del Sol is a protected site — a Bien de Interés Cultural, the highest tier of Spanish heritage designation — and the body that guards it, the local historic-heritage commission, treats permanent planting and fixed structures as alterations to a monument. The second is engineering: by the Ayuntamiento’s account, a concrete slab sits beneath the paving across the great majority of the plaza, the roof of the infrastructure below, leaving almost nowhere for a root ball to go. A proposal to plant a handful of trees in the one un-slabbed patch was rejected, the city said, precisely because the trees would have stood where the concrete happened to be missing rather than where any design logic put them.
Whether those constraints were truly immovable or merely convenient is the heart of the local argument. Critics point out that the same administration chose the slab-and-granite scheme in the first place, and that “the heritage commission won’t allow trees” is a more comfortable line than “we did not design for shade”. The mayor’s own blunt formulation, by mid-2025, was that not a single tree could be planted in the square. The honesty of that statement is not in doubt. The question is how the square came to be built so that it would be true.
The most expensive shade in Madrid
If you cannot plant a tree, you can hang a sheet. In June 2025 the city installed giant textile toldos — tensioned awnings — over the Puerta del Sol, billed as the first shade the plaza had carried in its hundred and sixty-three years. The headline cost of the canopies ran to roughly a million and a half euros; the seasonal choreography of taking them down, storing them and putting them back each year was budgeted at close to half a million more, pushing the total towards two million. The opposition on the city council, sensing a gift, called them expensive, ugly and stingy with actual shade. The local press settled on a tidier phrase: the most expensive shadow in Madrid.
The toldos are easy to mock and hard to dismiss. They are a confession rendered in fabric: an admission that the surface laid down in 2023 needs covering, paid for in an annual line item that did not exist before. They are also, on the hottest afternoons, real shade where there had been none. Both things are true, which is why the canopies have become the durable symbol of the whole affair — more than any speech, they are the city correcting itself in public, slowly and at a price.
A protected square where, by the council’s own account, not a single tree can be planted — so the city rents itself shade by the season instead.
On the Puerta del Sol toldos, Ayuntamiento de Madrid
Not the first frying pan
Sol was not the first square in Madrid to earn the nickname. When the Plaza de España re-opened in November 2021 after a long redesign, the inauguration photographs showed a broad, bright expanse with trees that looked thin and provisional against the scale of the stone. The city countered that more than a thousand trees had in fact been planted across the scheme; the critics, including planners who had wanted a genuinely green square, argued that the ambition to make the space cool and leafy had been only partly met. The sartén label attached itself to Plaza de España first, and then waited for Sol.
The pattern matters because it is a pattern. Across a run of central redesigns, Madrid kept reaching for hard, mineral, monumental surfaces in a city that now regularly crosses thirty-five degrees in summer and whose dense centre cooks under a textbook urban heat-island effect. The aesthetic is legible — clean sightlines, durable granite, a certain civic grandeur — and it is exactly the wrong instinct for the climate the city actually has. Each square, taken alone, had its defensible reasons. Taken together, they read as a municipal habit that summer keeps punishing.
The trees that came down
The harder edge of the same story is not about squares but about losses. By the count cited by Greenpeace and widely reported, Madrid has shed tens of thousands of trees since 2019 — a figure in the order of thirty-six thousand — to development, disease, drought and infrastructure. The most combustible episode came in early 2023, when the plan to extend Metro Line 11 was set to fell on the order of a thousand trees, some of them decades old, through the Madrid Río parkland and nearby green space along the Manzanares.
The response was unusually physical. More than a thousand people marched; the regional government, which runs the metro, paused and re-jigged the route under the pressure. When work resumed later in the year and crews returned with chainsaws to a smaller but still substantial number of trees, some protesters tied themselves to the trunks. The dispute folded neatly into the 2023 election season, with the felling becoming a campaign issue in its own right. Responsibility was split — the metro is the Comunidad de Madrid’s project, not the city’s — but to a resident watching a fifty-year-old plane tree go down, the distinction between regional and municipal authority was academic.
The ring around the city
And yet the same administration that built la sartén is also pursuing one of the most ambitious urban-greening projects in Europe. The Bosque Metropolitano — the metropolitan forest — is a planned green ring some seventy-five kilometres in length, stitching new woodland into the existing parks and scrub around the city’s edge to form a near-continuous belt. The published ambition is large: thousands of hectares of new planting linked into tens of thousands already there, well over a million trees and several million shrubs, chosen for drought tolerance — pines, junipers, oaks that can take the dry Castilian middle without constant irrigation. The headline price tag runs to roughly one and a half billion euros over its long horizon.
The logic is sound and the contradiction is glaring at once. A forest ring on the periphery does real work against the heat island and absorbs a meaningful tonnage of carbon by the city’s own projections. But it cools the edge, not the centre; it does little for the pensioner crossing the Puerta del Sol at three in the afternoon. A city can plant a million trees on its outskirts and still leave its most famous square as bare stone — and Madrid, for a season, did exactly that. The Bosque is the green ambition; Sol is the mineral instinct; the two belong to the same government and the same decade.
What the stone teaches
The European lesson here is not a tidy one about a mayor who saw the light. It is about how heat exposes design choices that looked merely aesthetic when they were made. A protected square, a concrete slab, a preference for clean granite over messy canopy — none of these were climate decisions at the time, and all of them became climate decisions the first August the thermal cameras came out. The toldos are what it costs to retrofit shade onto a surface that was never asked to provide it.
For the rest of the urban decade, the more useful figure than any single temperature reading is the gap between the two Madrids the city is building at once: the forest ring it is planting on the horizon, and the frying pan it laid down at the centre. Closing that gap is harder than either project alone, because it means designing the dense, monumental, heritage-bound core for a climate that the people who built it never imagined. Madrid has not torn up its concrete plan. It is, more honestly, learning in public — one rented summer of shade at a time — what the concrete plan cost.
Sources: Ayuntamiento de Madrid (Puerta del Sol remodelling and toldos budgets; Bosque Metropolitano programme); Comunidad de Madrid (Metro Línea 11 extension); Greenpeace España thermographic survey, July 2024; reporting in The Local Spain, El Español, Infobae, The Olive Press, The Daily Beast and World-Architects on the Puerta del Sol, Plaza de España and the Metro Line 11 tree-felling protests.
