Elevation Changes Along the Encierro Route: A Runner’s Topographic Guide

Most runners approach the encierro as a simple horizontal sprint. They are wrong. The 875-meter route is defined by elevation changes that affect everything: how fast the bulls run, where they struggle, how runners position themselves, and where injuries happen. Santo Domingo is a 10 percent grade uphill. Estafeta climbs at 2 percent for its entire length, barely perceptible until you are in the middle of it struggling to maintain position. Mercaderes banks and drops. Telefonica descends. The bullring is flat by design. Understanding the vertical topology of the encierro is the difference between a strategy that works and one that fails. Okdiario’s encierro photography captures how the gradient of the route affects both bull and runner momentum at different sections.

Santo Domingo: The Dominant Grade

Santo Domingo is the first 280 meters of the route, and it defines the entire run. It is a climb. According to sanfermines.net, the slope features “a steep slope with a gradient of up to 10 percent,” and the street is “boxed in between vertical stone walls.” Ten percent is a significant grade, steep enough that runners cannot maintain running speed and still feel in control. The bulls, however, run faster on this section than anywhere else on the route.

This apparent contradiction is explained by bull anatomy. The front legs of a bull are noticeably shorter than the back legs. Running uphill plays to this anatomical advantage. The herd is fresh, not yet tired, and the incline suits their body structure. For runners, Santo Domingo is the most exhausting section because they must climb against gravity while staying ahead of or alongside the bulls.

The walls on either side of Santo Domingo add another dimension. The street is not wide. Runners cannot easily move laterally. They are funneled upward in a corridor of stone. This creates compression. When the bulls approach from behind, there is nowhere to escape except forward or into the walls themselves.

The slope then levels off as the route enters the Plaza del Ayuntamiento (Town Hall Square), where the elevation change moderates but does not disappear entirely.

Mercaderes and Town Hall Square: Subtle Slopes

Most runners do not consciously register the elevation of Mercaderes and Town Hall Square. This is a mistake. The sections are deceptive.

Dennis Clancey points out what many overlook: “Town hall banks slightly to the left. Most people don’t realize, but Mercaderes is slightly downhill. And then the entirety of Estafeta is slightly uphill. It’s hard to tell that.” The fact that it is hard to tell does not make it irrelevant. The grade affects where the bulls run fastest and where they begin to tire slightly.

Town Hall Square is roughly 100 meters long and widens compared to Santo Domingo. The bulls transition from the steep incline to a more open space. The slight left bank means the herd must negotiate a turn while the grade shifts beneath them. Runners who have studied the route understand that this transition point is where the manada’s speed can modestly decrease, creating fractional opportunities for positioning.

Mercaderes follows Town Hall Square and continues the slight downward trend. For runners this is an advantage. The modest descent creates a natural acceleration zone, a place where momentum works with you rather than against you. For the bulls, the descent means they can recover slightly from the exertion of Santo Domingo while still maintaining speed.

Estafeta: The Uphill Run

Estafeta is 300 meters long, the longest straight section of the route, and it is uphill for its entirety. The grade is shallow, only 2 percent on average, but 2 percent sustained over 300 meters is a meaningful climb. This is why Estafeta feels so demanding, even to experienced runners.

Chapu Apaolaza, in Three Prayers for the Countdown (translated by Larry Belcher), provides a technical description of Estafeta’s elevation profile: “Estafeta is a street of legend…it has a slight slope, somewhat more pronounced at the beginning. Until the street is running parallel to the main square, it is uphill, where it then levels off and begins to run slightly downhill in the final section of the street.” This means the grade is not uniform. It begins steeper, moderates in the middle, then transitions to a gentle downhill near the end.

The psychological effect of climbing Estafeta, even at 2 percent, is significant. Runners have already exerted themselves on Santo Domingo. The bulls are beginning to fatigue but are still powerful. The uphill forces runners to maintain effort while the physical toll accumulates. This is where many runners reach a point of decision: continue at speed or conserve energy.

The street is also narrow and shaded, which adds to the sense of enclosure. According to sanfermines.net, it is “shady, and with a slight upwards slope of 2 percent.” The lack of direct sunlight combined with the uphill grade creates a distinct psychological environment compared to the bright Town Hall Square that precedes it.

Telefonica to the Tunnel: The Descent

After Estafeta, the route descends. The Telefonica section and the final approach to the bullring are the only parts of the route where gravity works in the runners’ favor. This is the moment where the physical toll of the climb reverses into a downhill run.

Sanfermines.net describes this section: “This is the final section of the route, the brightest and the only one with a gentle slope downwards.” The bulls are tired by this point, running slower than they did at Santo Domingo. The descent accelerates the final stage of the run.

The passageway leading to the tunnel, the callejon, is narrow, less than 4 meters wide at points, and the tunnel itself is 25 meters long and below the level of the spectator stands. This descent is where pile-ups occur, where runners stumble, and where the final moments of chaos before the bullring take shape.

The Bullring: Flat by Maintenance

The bullring’s sand surface is deliberately maintained flat. This is not accidental. According to Dennis, “The sand is flat by design and by maintenance.” The arena cannot have slopes or depressions. The afternoon bullfighters need a consistent, predictable surface. The maintenance crew works to ensure the sand remains level regardless of the damage the encierro and the morning’s events have created. Diario AS has noted in its coverage how the elevation changes affect herd speed, particularly on the Santo Domingo descent.

This transition from downhill descent to flat arena is sudden and biomechanically significant. A runner’s body is adapted to the descent coming down the callejon. The moment they hit the sand and the slope disappears, the mechanical relationship between gravity and motion changes instantly. Many runners lose their footing or stumble in the arena not because of the bulls but because of this unexpected elevation change.

Expert Insight: Dennis Clancey on Grade and Strategy

“Town hall banks slightly to the left. Most people don’t realize, but Mercaderes is slightly downhill. And then the entirety of Estafeta is slightly uphill. It’s hard to tell that.” “The sand is flat by design and by maintenance.”

— Dennis Clancey, founder of Encierro and member of La Unica Pena

Dennis’s observations about elevation are not theoretical. They reflect decades of observation and experience running the encierro. The fact that something is hard to perceive does not mean it should be ignored. The subtle grades on Mercaderes, Town Hall, and Estafeta compound throughout the route. By the time a runner reaches Telefonica, those accumulated elevation changes have affected their energy expenditure, their positioning, and their ability to maintain speed.

How Elevation Affects Bull Behavior

The elevation profile of the route is not neutral for the bulls. Their behavior changes with the grade.

On Santo Domingo’s steep uphill, the bulls run fastest because their body structure suits the incline. Their front legs, being shorter, are better adapted to pushing up a slope. Fresh, energized, and suited to the terrain, the herd accelerates dramatically. For runners, this is the most dangerous moment in the early part of the route.

As the elevation moderates through Mercaderes and Town Hall, the bulls maintain speed but no longer have the mechanical advantage of the uphill. This is where runners find fractional opportunities to position themselves and establish rhythm.

On Estafeta’s sustained 2 percent climb, the bulls begin to tire in earnest. The uphill gradient, combined with the distance already traveled, begins to slow the herd. The bulls are still capable of crushing a runner, but they are no longer accelerating. They are managing the grade.

By Telefonica, the downhill and fatigue combine. The bulls run slower here, according to sanfermines.net, because they are tired. The mechanical advantage of the descent helps them, but their energy is depleting. This is where loose bulls become most dangerous because they separate from the herd on Estafeta and are still present when the route descends.

Ray Mouton, in Pamplona (2002), notes the consequences: “The worst injuries have occurred at the bottom and at the top of the run, on Santo Domingo and in the callejon.” The two places where gravity creates the most extreme conditions are where injuries cluster. The bottom and the top of slopes are where control fails most easily.