The old city is made of the hill, and the hill has the holes to prove it

Here is a thing you can do in one day in Barcelona that costs nothing and that nobody puts in an itinerary.

In the morning, stand in front of the cathedral, or the Drassanes, or Santa Maria del Mar, and put your hand on the wall. In the afternoon, go up Montjuïc and stand in the hole that wall came out of.

They are the same rock, and the institutions that own both ends of the transaction say so in writing.

What the stone is

It is a sandstone — gres. The Ajuntament, on the castle’s own history pages, calls it plainly: one of the great riches of Montjuïc is the stone that makes it up, the gres. The city’s natural science museum describes it as compact and resistant, and as the base material of the city’s principal buildings.

The best description of what it looks like comes from the institution that has handled more of it than anybody. The Sagrada Família describes a stone whose cement is silicic, and whose colour range runs from light grey and greenish grey through beige, yellow, ochre and gold to purples and reds.

That range is why the old city is not one colour. Walk the Gothic Quarter looking for it and you will start seeing golds and greys and the occasional dull red in walls you had filed as “stone”.

On the age, we are going to be careful in a way that most pages are not. The Ajuntament’s sustainability portal describes conglomerates of around fifteen million years, Miocene, on the hill. That sentence is about a specific outcrop rather than about the building sandstone as a whole, so we are handing you the attribution instead of the tidy headline “Miocene sandstone” you will read elsewhere.

What was built out of it

This is the claim that circulates everywhere without a source, so here it is with four separate institutions attached, each vouching for its own list.

The Ajuntament, on the castle’s pages: most of Barcelona’s singular buildings have been built with this material: the Roman wall, the Roman temple, the first Christian church, the Romanesque and Gothic cathedrals, among others.

The natural science museum: Santa Maria del Mar, the cathedral, the Sagrada Família and La Pedrera, wholly or partly.

The maritime museum, about the building it lives in: the Drassanes — the medieval royal shipyards — were built with Montjuïc stone, and preserve hundreds of stonemasons’ marks. The shipyard is worth a visit on its own account.

The Sagrada Família, listing other people’s buildings: the Palau de la Generalitat, the Parliament of Catalonia, the city hall, the Llotja, the port customs house, the University of Barcelona, and the castle on top of the hill itself.

Two honest footnotes. Casa Milà is named by the natural science museum and by nobody else we could reach — the Sagrada Família’s long list leaves it out. And the Llotja is vouched for by the Sagrada Família describing somebody else’s building, which is thinner than a building vouching for itself. We are printing both, attributed, rather than laundering them into a flat statement.

So: the Roman wall that Barcino built, and the two great Gothic churches that came seven hundred years later, and the castle that spent two centuries pointing its guns at both of them — all out of the same hill.

The bit that closes the circle

The Sagrada Família’s own account of its stone is the best short history of this hill anybody publishes.

At the start of the works, in 1882, Montjuïc stone was used to begin the crypt. When Gaudí took over the direction the following year he asked that the building continue in the city’s own stone, and the apse and the Nativity façade were begun with it.

Then, from around 1954 — just as the Passion façade was starting — the shortage began to bite. And in 1957, extraction stopped suddenly and definitively. The Ajuntament dates the end of the workings to the same year.

Which leaves a basilica still under construction and a quarry that had closed. So in 1988 the Ajuntament ceded to it around a thousand cubic metres of Montjuïc stone recovered from the remodelling of the Olympic Stadium.

Read that slowly, because two of our other pages meet in it. The 1929 stadium was rebuilt behind its own façade for 1992 and its track was lowered eleven metres. The rock that came out went to the basilica that is still not finished — the same hill, delivered a second time, seventy years after it was first cut.

Where the holes are, and what they became

The hill was worked, on the natural science museum’s account, since the Roman period. The Sagrada Família pushes the start back further, to the Iberians; we are giving you both rather than picking.

Almost nothing survives of the Roman workings. The Ajuntament says only one Roman-era quarry is known in Barcelona at all, and it turned up by accident in 1989, during the works for the new access roads to the Olympic Ring. Quarrying carried on through the Middle Ages — the Ajuntament notes that the great constructions of that period are of stone from this hill.

How many quarries in total? The Sagrada Família estimates twenty-eight at various points on the mountain, some of whose faces are still clearly visible. That is an estimate by one institution and we are labelling it as one.

Two are named by the Ajuntament, and both are places you can go:

La Foixarda, worked from the mid-seventeenth century to the mid-nineteenth by the Barcelona family of quarrymen Foixart — which is where the name comes from. It is now a sports ground.

The Machinet, whose face the Greek Theatre was built against for the 1929 fair. The Sagrada Família adds that the millstones were especially well known from where that theatre now stands.

And then the reuses, which are the reason this page exists:

• The historic botanical garden hides, in the museum’s own words, in the depths of the old Foixarda quarry, in two old holes where the cool microclimate lets Eurosiberian species grow.
• The Costa i Llobera and Mossèn Cinto Verdaguer gardens were made in the bottom of two exhausted quarries — both of them.
• And the Fossar de la Pedrera is a worked-out quarry that the city used as a common grave until 1979.

That is the shape of the whole hill. Barcelona took the rock out to build itself, and then put a theatre, two gardens, a climbing wall and a mass grave into the spaces it had left.

What we are not going to tell you

Three quarry names circulate and we are dropping all three.

• Can Sató: nothing found, anywhere institutional.
• El Mussol: the Ajuntament uses Carrer Pedrera del Mussol as a street name. A toponym is not a documented quarry history.
• La Gardunya: that is a square in the Raval, on the back of the Boqueria. It is not on this hill, and printing it would be repeating somebody else’s confusion.

We are also not telling you that the Morrot — the sheer seaward cliff — was quarried for building stone. What the Ajuntament documents there is something else and older: the jasper workshop of the Morrot, the oldest trace of human occupation on the mountain, where nodules of jasper were extracted. That is a different material, a different purpose and several thousand years earlier.

How to see it in an afternoon

You do not need a route for this. You need to know what you are looking at.

Go up from Plaça d’Espanya, and on the way through the fairground stop at the Greek Theatre and look at the wall behind the stage. That is not a set. That is the quarry face.

Carry on to the gardens and notice that you keep dropping into enclosed hollows with their own microclimate — because you are standing at the bottom of somewhere the stone came out of. Then look across at the castle, which is built of the hill it is standing on.

And the next morning, go down into the old city and look at the cathedral again.

The version with someone doing the talking

Our Montjuïc walking tour takes the hill in the order it happened — the fair, the castle above it, the quarry behind it — and this is the thread running under all three of them, because the mountain was a resource long before it was a fortress or a fairground.

The other end of the same story is our Gothic Quarter walk, which spends two hours in buildings made of this rock arguing about which centuries they are actually from.

If you are working out whether the hill deserves an afternoon: is Montjuïc worth it. If you are working out how to get up it: how to get to Montjuïc.

One more hole with something in it, and its name is on the heritage file: the Teatre Grec sits in the old pedrera Machinet, which is in the piece on Poble-sec and the Paral·lel along with the rest of what is at the bottom of this hill.

Two pages that grew out of this one: the racing circuit that used the park’s roads from 1933, and the reason the hill is made of different rock from everything around it — and what that rock did to the ground the rest of Barcelona stands on.