You reach the Xalet del Catllaràs on a forestry track above La Pobla de Lillet, in the Berguedà, about 130 km north of Barcelona. The road climbs through pine woods past the Santuari de Falgars, and then, at 1,371 metres, the trees open onto a meadow and there it is: a steep grey pitched form with a rendered gable end, dormers marching up the slope of the roof, a single flagpole and nothing else around it. We went up this summer expecting a curiosity and came away thinking about it for weeks.
The restored Xalet del Catllaràs in summer 2026, its catenary section, pebble-dashed base and rebuilt external stair once again matching the 1905 photograph. RISE Design Studio.
The building only makes sense once you understand the industry it served. At the start of the twentieth century Eusebi Güell, Gaudí's lifelong patron, owned the Asland cement company and was building a new factory at the Clot del Moro, near Castellar de n'Hug, at the source of the Llobregat. The kilns needed coal, and the coal was in the Catllaràs range, a long way above the nearest village.
Güell's answer to the distance was an aerial cableway. Coal came down from the mines by telefèric to La Pobla de Lillet and then on by rail to the factory. Standing in that meadow and picturing a cable car strung across the valley in 1904, before the road existed, tells you a good deal about the ambition of the operation.
The engineers setting up the mines, many of them British, needed somewhere to live close to the workings, and Güell needed a reason for them to agree to move to a remote corner of the Pyrenees. His answer was to give them a building nobody else had. He asked Gaudí to design it. Work started in 1902, while Park Güell was also on site in Barcelona, and the photographs in the archive show it finished by 1905.
The Xalet del Catllaràs shortly after completion in 1905, with the pebble-dashed base, projecting dormer hoods and the original stair. Archive image.
The xalet is a rectangular block of ground floor, first floor and attic, but the section is the point. The whole thing is a single vault, catenary on the inside and pointed on the outside, so the roof and the long walls are the same element. The ridge of the vault is the ridge of the roof. Windows are cut into the slope as dormers with sloping hoods, and the two gable walls have very few openings. It is a structural idea before it is a stylistic one, and it is the same idea that carries the Sagrada Família on a completely different scale.
Inside it was plain and tightly planned, about 396 m² in all: six dwellings, two per floor, with kitchens and dining rooms on the ground floor, and the floor plates shrinking as the vault closes towards the top. The attic apartments were single open spaces. Two chimneys served the stoves, one rising through the vault and one attached to a side wall.
We were able to get inside, and the attic is the room to see. The vault has been plastered white and the two gable walls left as exposed rubble stone, so you read the catenary twice, once as the smooth curve overhead and once as the rough profile of the end wall with a single timber casement set into it. The dormers cut deep splayed reveals into the curve and throw light down the slope of the vault. A steel beam now runs along the ridge, a later intervention, and the floor is a speckled terrazzo. It is a bare room and it does not need anything else.
The most telling detail is how the floors were allocated. The ground floor, the coldest, went to maintenance and service staff. The middle floor, the best insulated, went to the technical staff. The attic went to junior staff. Thermal comfort was distributed by rank, and the section did the sorting. As a practice that spends its days on fabric performance and where heat actually goes in a building, we found that both very honest and very of its time.
The first-floor landing of the rebuilt stair, with the scalloped pebble ridge and corbelled chimney cap behind. RISE Design Studio.
The old photograph tells the story of what was lost. The original external stair was a semicircular masonry volume that stepped up the front of the building, linking all three floors and sheltering some of the daily life of the house within it. It was the one gesture on the elevation that read as unmistakably Gaudí.
Later decades were not kind. The archive photographs run in sequence from 1902 through 1905, 1907, 1920, the late 1930s, 1944, 1970 and 1977, and you can watch the building lose itself frame by frame. Coal extraction stopped with the Civil War and the fabric began to deteriorate. In 1971 it was converted into a casa de colònies, a children's holiday camp, with numerous alterations. The masonry stair was removed and replaced with a lightweight steel one, the roof was slated, and the building was left looking like an oddly shaped hostel. The bones were still there but the character had been stripped off.
From 2015 a first phase of recovery removed the steel stair and rebuilt the original masonry one, and by 2020 the works were reported complete, with the building expected to return to use as a mountain refuge. When we visited there was still site fencing and building material around the base, so something is evidently ongoing. It is a long, slow rescue, but the stair is back and the building reads properly again.
The arched passage at the foot of the stair, where the sloping roof-wall meets the ground floor. RISE Design Studio.
For a century this was a building everyone assumed was Gaudí's without a document to prove it. The strongest written evidence was a 1946 piece in the Madrid magazine Cortijos y Rascacielos in which the architect Viladevall reported that Domènec Sugrañes, Gaudí's collaborator and successor at the Sagrada Família, had told him Gaudí was the author.
The building itself has been making the argument for longer than the paperwork. In 2001 the practice ROA Arquitectura, led by Roger Orriols, was commissioned by the Ajuntament de la Pobla de Lillet to carry out a historical and constructional study of the xalet and to redraw it as originally built. Set side by side, the 1902 plans and the 2001 survey show exactly what had been lost: the semicircular stair volume on the ground floor, the two-per-floor apartment layout, the open attic. Orriols also read the building against the rest of Gaudí's work and found a consistent set of fingerprints. The catenary section is the same geometry as the attic of La Pedrera. The ventilation strategy, with air drawn through the building, is the approach used at Casa Batlló. The dormered mansard roof echoes the Bodegas Güell at Garraf. The chimney is designed to pull draught by the Venturi effect, as at Bellesguard. And the proportion of base to height sits on the golden ratio, which Gaudí also used at the Sagrada Família. None of those is a signature on a drawing, but together they are hard to explain any other way.
In February 2026, in the centenary year of Gaudí's death, the Catalan heritage department published a study led by Galdric Santana Roma, chair of Gaudí studies, concluding that the xalet is Gaudí's work. The attribution is deliberately limited: it covers the early stages of the project only, since Gaudí did not supervise the build and the finished building did not follow his design faithfully. That caveat matters. What you see on the hill is a Gaudí idea, built and then altered by other hands over 120 years, rather than a Gaudí building in the sense that the Casa Batlló is.
The semicircular masonry stair, removed in the 1970s and rebuilt from 2015, links all three floors from the outside. RISE Design Studio.
The factory the coal was feeding is a separate visit and deserves a proper one. The Asland works at the Clot del Moro were designed by Rafael Guastavino, the Valencian architect who took the Catalan tile vault to the United States, patented it there and built it into Grand Central and hundreds of other buildings. Back in Catalonia, working with Güell, he designed a cement factory in the same thin brick vaults, stepping down the hillside in tiers over a metal frame. It operated from July 1904 until the 1970s and is now the Museu del Ciment.
The Asland factory at the Clot del Moro during construction, Rafael Guastavino's tiers of Catalan vaults stepping down the hillside above the Llobregat. Archive image. RISE Design Studio
We only had time for a brief look at the factory, enough to know we need to go back. What did stop us in our tracks was the quarry above it, where the limestone was blasted out of the mountainside to feed the kilns. The scale of the cut is hard to take in. Between the quarry, the vaulted factory, the cableway and the house for the engineers, you are looking at a complete industrial system designed by two of the best architects of their generation, in a place that today feels like the end of the road.
The factory as it stands today, its vaulted tiers open to the sky, the Museu del Ciment in the lower levels and the limestone quarry scarring the mountain behind. RISE Design Studio.
Three things stayed with us. The first is that the section of a building can carry everything: structure, envelope, plan and even the social order of the people inside it. The second is how much a single removed element can cost a building, and how much it gives back when it is reinstated. The third is that patronage and industry produced some of the most interesting architecture in Catalonia, well away from the city tours.
If you are planning a trip, La Pobla de Lillet also has the Jardins Artigas, a small Gaudí garden from the same period and the same patronage network, and the Tren del Ciment runs from the town up to the museum. Allow a full day and go in summer when the track is open.
If you are thinking about a project of your own, whether a mountain refuge or a Victorian terrace, we'd be glad to talk it through. Please do get in touch.
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