The barreras (barriers) are the wooden fences that run along sections of the encierro route, marking the boundary between the street where the bulls run and the areas beyond. Most runners and spectators see the barreras and think about safety: a place to step out if things go wrong, a structure that could offer some protection if a bull gets close. That reading is incorrect, and it can be dangerous. The barreras and the vallados, the fenced buffer zones directly behind them, exist to manage crowd movement, to give medics access to injured runners, and above all to keep the bulls on the route. Understanding what the barriers actually are, where they exist and where they do not, and what they mean for a runner’s positioning on the route is part of running the encierro with genuine preparation.
What the Barreras Look Like on the Route
The first thing most people get wrong about the barreras is assuming they are continuous along the full route. They are not. Dennis explains how the limits of the route actually work:
“The barriers are very different depending on what part of the route you’re on. For much of Calle Estafeta, the facades of the buildings are the actual left and right limits of the route. You don’t need to put wooden barriers there. They just board up the facades of the buildings.”
Dennis Clancey, Founder of Encierro
Where wooden barriers are in place, three horizontal wooden slats connected by metal-reinforced posts mark the edge of the route. They are set into the ground early on the morning of the run and are built to withstand the force of a bull. Behind that inner barrier, the one that marks the actual limit of the run route, there is a gap of roughly ten to twelve feet before the outer barrier where spectators stand.
Dennis describes what fills that gap:
“Wherever there’s a vallado, there’s a no man’s land behind it. You can only have medics, police, and a select number of photographers.”
Dennis Clancey, Founder of Encierro
That no man’s land is not incidental. It is the reason the barrier system functions at all.
The Purpose of the Vallado: Emergency Access and Crowd Management
The buffer zone between the inner and outer barriers serves two functions. The first is medical. If a runner goes down on the route, medics need to reach them and move them out of the path of the continuing herd. Dennis explains:
“If someone’s injured, you want to be able to pull them to a place that’s safe, and it’s not crowded with people. If people were crowded along the sides as spectators, that would be a big problem.”
Dennis Clancey, Founder of Encierro
The second function is crowd control before the run even begins. The police use the no man’s land to pull people off the route who should not be there:
“It gives the police a place to easily take people off the run route if someone is seen as intoxicated or not dressed appropriately. It gives space for the police to take them off the run route and speak to them.”
Dennis Clancey, Founder of Encierro
Both functions serve the same purpose: maintaining a clear, managed corridor where the bulls have right of way. None of this infrastructure is designed to give runners a way out.
Barrera Locations Along the Route
The section with the most concentrated barrier presence is the Town Hall area:
“Town Hall is exclusively barriers, double barriers basically.”
Dennis Clancey, Founder of Encierro
At the Plaza Consistorial, the entire perimeter uses a double barrier system. The inner barrier marks the route boundary. The outer barrier manages spectator access. The no man’s land between them is where medics and police operate.
From the corral up Calle Santo Domingo, the left side near the market has barriers positioned along the street while the right side is bordered by high stone walls and the bastion wall. On Calle Mercaderes, the facades of buildings on both sides initially form the limits. Partway through Mercaderes, past a bank building, barriers begin on the right side and continue as the route approaches La Curva. On Calle Estafeta, as Dennis notes, most of the street is bordered by building facades, not wooden barriers.
Bajada de Javier: What That Barrier Is Actually For
When runners ask about the first exit point on Estafeta, the answer is Bajada de Javier, the first cross street intersection after La Curva. But the reason barriers exist at Bajada de Javier is not to give runners a way off the route. Dennis explains why they are there:
“You don’t want the bulls running into another street. Prior to getting to Bajada de Javier, it’s the facades of the buildings on Estafeta that are the barriers. When you get to Bajada de Javier, you need a barrier there. Otherwise, the bulls would be able to run onto that street that runs perpendicular to Estafeta.”
Dennis Clancey, Founder of Encierro
The barriers at Bajada de Javier exist to keep the bulls on the route. If a runner wants to step off at that intersection after the bulls have passed, they can do so, but it requires crouching down and threading through the gaps in the three horizontal wooden slats. Dennis is clear about when that is appropriate:
“You’re only getting off the run route once the bulls have passed you. You wouldn’t attempt to do that as the bulls are inbound.”
Dennis Clancey, Founder of Encierro
Medical Positioning and Ambulance Access
The location of the barreras is directly tied to where medical personnel are positioned on the route. Dennis explains why Mercaderes is the center of that deployment:
“In Mercaderes is where there’s the biggest concentration of medical personnel and you have ambulances as well. Because it’s midway along the run route.”
Dennis Clancey, Founder of Encierro
From the midpoint of the 875-meter route, medics can reach any section with minimal delay. When a runner is injured and moved behind the inner barrier, evacuation can begin immediately. Dennis explains the routing:
“It’s very quick to be able to take an ambulance out through Plaza de Castillo out to the hospitals.”
Dennis Clancey, Founder of Encierro
The barrier system and the medical deployment are designed together. One enables the other.
Why Runners Cannot Use the Barreras as Escape Routes
The most dangerous misconception runners bring to the encierro is that the barreras offer a way out when the bulls are close. Dennis explains why that does not work:
“The route is so crowded that you’d be fighting through people trying to get through. Because you have stopped moving with forward momentum along the run route, you yourself start to become a barrier to other runners. It’s dangerous to other runners and to yourself to try to get off the run route because you’re not moving, and those bulls are moving incredibly fast.”
Dennis Clancey, Founder of Encierro
There is also an institutional dimension to this that most runners do not know about. The police enforce it directly:
“The police won’t even let you get off the run route if the bulls are inbound. They’ll tell you, ‘Keep running, keep running, keep running.’ They won’t let you get through that barrier as the bulls are inbound. By you attempting to get through the barrier, you are creating a hazard to everyone on the run route.”
Dennis Clancey, Founder of Encierro
Attempting to climb the barrier is equally dangerous. Dennis has seen the consequences:
“If you’re on that barrier, you’re a waiting target for a horn. It’s not quick to get over a barrier when a bull is nearby, largely because of the number of people that are crowding the side of the route. I’ve seen people trying to get up on the barrier when bulls are close getting gored by bulls. You want to stay on your feet, you want to keep moving, and you want to move away from the bulls.”
Dennis Clancey, Founder of Encierro
What Happens When a Suelto Separates from the Herd
A separated bull, a suelto, is the scenario where the instinct to find cover feels strongest. It is also the scenario where that instinct is most likely to result in injury.
The first time Dennis ever watched the encierro was in 2007, the day before he ran for the first time. He describes what he saw:
“Someone on the run route stood in a doorway, hoped a bull wouldn’t find him. Everyone else ran away. His plan was to stay in place. The bull saw him, went after him. The bull picked him up by its horn and threw him in the street.”
Dennis Clancey, Founder of Encierro
The people who ran were not hurt. The one person who stopped moving was. Dennis is direct about what that means:
“Stay on your feet and take off running away from a suelto bull. Never decide to stay in place, because then it’s random whether you get found and injured by the bull.”
Dennis Clancey, Founder of Encierro
A doorway, a corner, and a barrier are all variations of the same idea: find a place to stop and hide. The evidence runs the other direction.
The Right Mental Model: How to Think About the Barreras
If the barreras are not escape routes and the police will not allow runners through them while the bulls are inbound, what is the right way to think about them? Dennis explains:
“The only importance of understanding where the barriers are is knowing where to get off the run route once the bulls have actually passed you. It is having a plan: I think I’m going to run to whatever position along the run route, and then I’ll have a place where I can get out after the bulls have passed.”
Dennis Clancey, Founder of Encierro
This is the correct mental model. The barreras and the vallados matter for exit planning after the run, not for escape during it. A runner who knows where the barriers and intersections are on their section of the route knows what comes after the herd goes by. That is a different and more useful thing to know than whether the barriers could protect you while the bulls are still moving.
Vocabulario: Spanish Terms Related to the Barriers and the Route
Barrera (bah-REHR-rah): A barrier or fence marking the boundary of the run route. The term most commonly used in English-language coverage of the encierro.
Vallado (vah-YAH-doh): The barrier system including the buffer zone behind it. Used interchangeably with barrera in common usage, but carries the specific implication of the no man’s land access corridor reserved for medics and police.
Suelto (SWEL-toh): A bull separated from the herd. The scenario where the instinct to seek cover is strongest, and where staying on your feet and running is most important.
Mercaderes (mer-cah-DEHR-es): The street where the highest concentration of medical personnel and ambulances are stationed during the run.
Bajada de Javier (bah-HAH-dah deh HAH-vee-air): The first cross street on Estafeta after La Curva. Barriers close off this intersection to keep the bulls on the route. Runners can exit through the barrier slats here, but only after the bulls have passed.
Ayuntamiento (ah-yoon-tah-mee-EN-toh): Town Hall. The plaza section with the most concentrated barrier presence on the entire route.
Frequently Asked Questions
Can I use the barreras to escape if a bull is close?
No. The police on the route will not allow runners to exit through the barriers while the bulls are inbound. Trying to stop and force through a barrier while the herd is still moving turns you into a stationary obstacle in a packed corridor. The bulls are moving at high speed. Stay on your feet, keep moving, and run away from the threat.
Where are the barreras located on the encierro route?
Barreras are concentrated at Town Hall, along sections of Santo Domingo and Mercaderes, and at cross street intersections on Estafeta starting at Bajada de Javier. Most of Estafeta is bordered by building facades rather than wooden barriers. The facades serve as the natural left and right limits of the route in those sections, and the buildings are boarded up for the run.
What is the vallado and the no man’s land behind the barriers?
The vallado refers to the barrier system including the buffer zone between the inner and outer barrier. That no man’s land, roughly ten to twelve feet wide, is reserved for medics, police, and a select number of photographers. When someone is injured on the route, they are moved through the inner barrier into this space so medics can work without obstruction and evacuation can happen quickly.
Why is there a barrier at Bajada de Javier on Estafeta?
The barrier at Bajada de Javier is there to prevent the bulls from running onto that side street. It is not designed as a runner exit. Runners can squeeze through the horizontal slats of the barrier at that intersection after the bulls have passed, but it requires a deliberate physical maneuver and is only appropriate once the herd is clear.
What should I do if I see a suelto?
Stay on your feet and run. A separated bull is not drawn to movement. It is drawn to whatever is easiest to find. The worst position is stationary. People who run away from a suelto are almost always fine. People who try to hide in a doorway, against a barrier, or in a corner are the ones who get found.
Understand the Barriers, Know the Route
The barreras and the vallado system are part of the encierro’s infrastructure, not a safety net for runners. Understanding what they are, why they exist, and where they are located is part of building real spatial awareness on the route. Our preparation sessions cover the full route geography, including barrier locations and what they mean for your positioning. Study the route map or book a tour with Encierro and walk the route with someone who has been on it every San Fermín since 2007.