La Curva de Estafeta (pronounced lah COOR-vah deh es-tah-FEH-tah) is the sharp right turn where Calle Mercaderes meets Calle Estafeta on the encierro route in Pamplona. It is a roughly 90-degree turn that forces a herd of bulls traveling at full speed, carrying downhill momentum from Mercaderes, to change direction abruptly. This single point on the 875-meter encierro route is where the physics of the run are most visible: 500 to 600 kilogram animals generating enormous force and momentum must negotiate a turn that the geometry of the streets was never designed to accommodate smoothly. What happens at La Curva in any given encierro often determines the character of the entire run that follows.
The Physics of La Curva: Force, Momentum, and Cobblestones
The herd approaches La Curva generally toward the left side of the course, having picked up speed on the slight downhill of Mercaderes. As Mat Dowsett describes in “Encierro!” (2003), the bulls have generated a great deal of force and momentum by this point and are suddenly faced with a sharp turn. What happens next depends on several factors: whether the streets are wet or dry, whether the herd is tightly packed or strung out, and whether the bulls have run this route before.
The condition of the cobblestones (adoquines) at La Curva has been a concern for decades. In recent years, the city of Pamplona has begun applying an anti-slip treatment to the stones before the start of San Fermin.
“It’s a solution that they put down right before Fiesta that essentially cleans out the pores of the stones so the stones have more traction.”
Dennis Clancey, Founder of Encierro and member of La Única Peña
This treatment started at La Curva and has since been extended to other sections of the route, including the Plaza del Ayuntamiento. The reasoning is practical.
“The intent of the city is to make sure that the run happens as efficiently as possible and having bulls slip out, bulls potentially getting injured is counter to that aim.”
Dennis Clancey, Founder of Encierro and member of La Única Peña
Before the treatment became standard practice, the spectacle at La Curva was often more extreme. Bulls would slam into the outer barreras (barriers), lose their footing on the slick stones, and sometimes pile up entirely. The anti-slip solution has not eliminated these outcomes, but it has reduced their frequency and severity.
How the Herd Splits at La Curva
One of the defining characteristics of La Curva is its tendency to break the herd apart. According to Mat Dowsett in “Encierro!” (2003), the sharp 90-degree turn invariably causes the herd some difficulty and often results in the bulls being separated from the cabestros (steers). The cabestros run the route every day during the eight days of San Fermin. They are lighter, more sure-footed, and capable of learning the course. This means they may take La Curva cleanly and head up Estafeta while the bulls are still wrestling with the turn behind them.
When this separation happens, the dynamics of the run change dramatically. The cabestros are no longer guiding the bulls. A toro suelto (a bull separated from the herd) is an unpredictable animal, and the sections of the route after La Curva, particularly Calle Estafeta and the Telefonica stretch, become more complex for everyone on the street.
That said, outcomes at La Curva are never guaranteed. Dowsett recounts in “Encierro!” standing at La Curva on a rainy day when every experienced runner expected chaos. The bulls came through as a tight pack that barely brushed the barriers. The result was a particularly fast and clean run. As Dowsett writes, anything can happen in the encierro.
The Barrier Layout at La Curva
The right side of the course at La Curva uses the natural intersection of the streets along with the barreras running down from Mercaderes to create the turn. On the left, the entire side is boarded off with solid barriers. This cuts off the continuation of Mercaderes and forces the herd into Calle Estafeta. A solid metal gate positioned a few meters up on the left side can be closed after the herd passes, preventing any turning bulls from going too far back down the course.
The barriers at La Curva are always densely populated with spectators, but the front positions are typically occupied by official photographers and police. The photographers covet this location for its dramatic imagery: the moment when the herd collides with the outside of the turn is one of the most photographed moments of every encierro.
The Inside of La Curva Is Not a Safe Zone
A common misconception is that because the bulls tend to drift toward the outside of La Curva, the inside of the turn is a safe place to stand. This assumption is incorrect and potentially serious.
“I think one of the dangerous [assumptions] for someone is that because the bulls are more likely to go to the outside, that it’s safe to be on the inside and not be moving.”
Dennis Clancey, Founder of Encierro and member of La Única Peña
The police are active in enforcing that runners cannot stand stationary on the inside of La Curva. This is not arbitrary. A bull that recovers from the turn and straightens out, or one that separates from the pack early, can cut toward the inside with no warning. A runner who is standing still in that space has no time to react.
The Runner’s Code at La Curva
La Curva de Estafeta attracts many of Pamplona’s most experienced and committed mozos (runners). As Mat Dowsett observes in “Encierro!” (2003), these runners congregate at the bottom of La Curva with the specific intention of running up Estafeta amidst or in front of the herd. This requires a combination of skill, judgment, timing, speed, and an acceptance of the outcome. The technique of picking a route through fallen or lagging bulls to get in front of the pack is sometimes described as “threading the needle.”
These experienced runners take exception to tourists and newcomers blocking their path at La Curva. But Dennis frames this not as elitism, but as a philosophy of responsibility.
“I think it’s a responsibility of runners to help in the responsible execution of the run.”
Dennis Clancey, Founder of Encierro and member of La Única Peña
The principle applies everywhere on the route, but it is most visible at La Curva because the space is compressed and the consequences of a blocked path are immediate. Dennis is direct on the subject of runners who feel entitled to occupy space on the route without the ability or intention to actually run.
“I don’t think runners that understand the tradition and respect the tradition should ever approach the run with a sense of entitlement to be on that run route.”
Dennis Clancey, Founder of Encierro and member of La Única Peña
“When you get on the run route, you need have your full faculties and be able to move and get out of the way. And if you expect to be respected by others, you need to be able to demonstrate that.”
Dennis Clancey, Founder of Encierro and member of La Única Peña
This is not about excluding anyone. The philosophy of San Fermin, and of the encierro specifically, is that everyone is equal on the street. First-timers and veterans run the same route under the same conditions. But the responsibility that comes with stepping onto that route is real, and at La Curva, where there is no margin for error, that responsibility matters most.
How La Curva Was Shaped Over Time
La Curva de Estafeta has not always looked the way it does today. According to Mat Dowsett in “Encierro!” (2003), the curve was originally much more square and did not naturally draw the bulls around the corner. Over decades of experience running the encierro, the city refined the barrier placement and street geometry to create the more gradual arc that exists now. The raised pavements on Estafeta and Mercaderes were removed in 1998, further smoothing the surface transition.
The evolution of La Curva reflects the broader history of the encierro itself: a tradition that has been continually refined through observation, experience, and the practical need to manage the movement of powerful animals through medieval streets.
What to Watch for at La Curva as a Spectator
For those watching from the barreras or from a balcony overlooking La Curva, the key things to observe are the herd’s cohesion and the condition of the streets. A tightly packed herd that takes La Curva together typically means a faster, cleaner run on Estafeta. A herd that splits at the turn, with one or more bulls separated, signals a more complex and unpredictable run ahead.
The sound also changes at La Curva. The pounding of hooves shifts from the echo of Mercaderes’ narrow corridor to the broader acoustics of Estafeta. Experienced spectators listen for the change in rhythm that indicates whether the bulls have maintained their stride through the turn or have stumbled.
Video coverage from RTVE’s encierro broadcasts frequently isolates La Curva because it is the single point that most reliably determines the narrative of each morning’s run.
Vocabulario: Key Spanish Terms for La Curva
La Curva de Estafeta (lah COOR-vah deh es-tah-FEH-tah): The sharp right turn from Calle Mercaderes into Calle Estafeta. The most famous single point on the encierro route.
Cabestros (cah-BES-trohs): The steers that run with the bulls, guiding them through the route. Lighter and more sure-footed, they run the course all eight days of San Fermin.
Toro suelto (TOH-roh SWEL-toh): A bull that has become separated from the herd. Separated bulls are unpredictable and change the dynamics of the run.
Mozo (MOH-tho): A runner in the encierro. The term carries no hierarchy; it applies to first-timers and veterans equally.
Pastores (pahs-TOH-res): The herders who run behind the bulls, guiding stragglers and managing the flow of the herd through the route.
Frequently Asked Questions
Why is La Curva de Estafeta the most famous point on the encierro route?
La Curva is a roughly 90-degree right turn that forces bulls traveling at full speed to change direction abruptly. The physics of the turn, combined with the variable conditions of the cobblestones, make it the point where the herd is most likely to split, stumble, or collide with the barriers. What happens at La Curva typically defines the character of the entire run.
Is the inside of La Curva safe for runners?
No. While bulls tend to drift toward the outside of the turn, the inside is not safe. Bulls can cut toward the inside unpredictably, and police actively prevent runners from standing stationary on the inside of La Curva. Every runner at this point must be moving.
What is the anti-slip treatment applied to La Curva?
The city of Pamplona applies a solution to the cobblestones before San Fermin that cleans the pores of the stones, increasing traction. This treatment started at La Curva and has been extended to other sections of the route. It reduces but does not eliminate the risk of bulls slipping on the turn.
Where do experienced runners position themselves at La Curva?
Many of Pamplona’s most experienced mozos start at the bottom left of La Curva with the intention of running up Calle Estafeta alongside or in front of the herd. This requires significant skill and timing. These runners expect the space to be clear of stationary people who are not actively running.
Experience La Curva with Runners Who Know It
La Curva de Estafeta is a place where seconds matter and the margin between being positioned correctly and being in the wrong spot is measured in centimeters. Our instructional walking tours of the encierro route break down La Curva from the perspective of runners who have taken that turn with bulls at their backs. Book a tour with Encierro and see La Curva from the street, not from a photograph.