It was dusk in Barcelona, and I was sitting on a bench on the campus green, pretending to look at my planner. A growing crowd of students morphed and moved around me, and the lower the sun got the louder they became, laughing, kicking off shoes, drawing signs, changing clothes. Some were putting on tutus or other costumes. Others were winding a long black length of cloth around their waists, one person holding the fabric taut while the other person turned slowly into it, bracing their bare feet against the grass. The fabric was so taut, the person being wrapped was standing almost at a diagonal; they would have fallen to the ground if the other person had let go. Absolutely everyone was speaking Catalan.

I was there for castells practice, but as I watched a guy next to me pull on a ski mask, I realized that I did not know the first thing about what this entailed. I had only learned about castells four hours earlier, on a class excursion to Tarragona, where a photo of a pillar made of people standing on each other’s shoulders hung from a city wall. “Human towers,” the trip coordinator explained, “a Catalonian tradition for centuries.” She told us there was a castells group at Universitat Pompeu Fabra, where I was studying, and sent out an email to all of us with the details. There was a practice that night at seven.

A curly-haired girl wearing bear ears was sitting on the bench across from me. ¿Hablas inglés? I asked. She did. When I introduced myself and asked if this was the castells group, she responded with a deluge of information delivered with incredible warmth. Beginners are over there by the wall, the costumes are for the different subgroups of the team, we all have nicknames, we’ll be warming up for a while before practice starts, there’s a guy around here who works with newcomers, and was I in the group chat yet?

The beginners were climbing up and down from each other’s shoulders, holding vertical bars that ran up the side of the building for balance. The girl with bear ears introduced me to a short, smiley redhead by the wall. He was Catalan American, his English tinged with a faint accent. The girl gave me a brief lesson on technique: Stand close to the person in front of you, your front to their back. Put your foot on the inside of their leg as high up as it will go and clasp their shoulders. Pull your body up, then put your foot in the faixa, the black strip of cloth wrapped around their middle. My faint self-consciousness about all this grabbing and grappling evaporated in the face of the redhead’s nonchalance; he stood there as if waiting for the bus.

My first attempt was a failure that we shall not dwell on. On my second attempt, I made it up. I propped myself high on the redhead’s back, dug my toes in the faixa, and stood up onto his shoulders, gripping the iron bars in front of me for support. I felt a twinge of vertigo. All three of us cheered.

Back on the ground, still buoyant with adrenaline, I saw, through the crowd, someone start to climb up on a guy’s shoulders in the middle of the grass. There was nothing around for either of them to hold onto but each other. When the climber planted her feet, she stood up carefully, knees slightly bent.

As a second person began to ascend, the crowd went silent. It is hard to overstate just how swiftly this silence fell and how deeply it stretched. A group of people surrounded the man at the base of the castell, obscuring him from view. In perfect silence the second climber planted one foot and then another on top of the first climber’s shoulders.

Unbelievably, another person began to ascend. She climbed swiftly, moving somewhat like an inchworm on a plant’s stalk, folding and unfolding. All their faces were set, their gazes fixed.

Just before she reached the top, the unseen man at the bottom of the tower uttered one word in Catalan, and the whole base of people contracted like a fist closing, everyone pushing in all at once. The final girl descended swiftly, and as the tower disassembled itself so did the silence, and the crowd was a crowd again.

Many castells were constructed and taken down over the two-and-a-half-hour-long practice. For a number of them I joined the pinya, the crowd on the ground that pushes inward and keeps the person at the base from buckling under the accumulating weight.

The redhead told me that people in the pinya should resist the urge to watch the tower being built and should tuck their heads instead, to avoid a broken neck if the tower were to fall. I got used to the physical closeness of the pinya—having strangers’ bodies pressed into mine, resting my forehead against unfamiliar shoulders—but the thing I never got used to was the silence. Every few moments during the construction of a castell, there was only a tense word or two of direction from the club leader on the ground or a sharp, labored sound from the people at the base.

Other than that, we stood in silence and darkness, heads bowed, eyes closed, with nothing but the knowledge that something spectacular was being assembled above our heads.

Miller was a student in the Barcelona: Civilization in the Western Mediterranean program in Autumn Quarter of 2025.