PAINANI
PAINANI

PAINANI · RUN / LOCAL

67 · Puerto Rico, United States

El Yunque

Run a paved 2.6 km out-and-back through sierra palm and cloud forest to a 1937 stone tower at 941 m in the only tropical rainforest in the US national forest system.

Trail runningOut and back
2.6 kmDistance180 mElevation gainEasy mediumSite gradeRío GrandeNearest base

Site grade

Easy mediumFeatured

180 m of gain in 1.3 km on a paved but slick path, at 30 °C and full humidity, finishing on a stone tower's stairs. Short and steep; the rain is the difficulty.

The experience

Around 180 m of climbing in 1.3 km on cement, asphalt and gravel, wet almost every day, at 30 °C and full humidity. Nothing technical; the gradient and the surface set the pace.

El Yunque is the only tropical rainforest in the US national forest system, and Mt. Britton Tower is its best-preserved CCC structure, built in 1937 and listed on the National Register.

The forest was set aside by the Spanish crown in 1876 and is administered by the USDA Forest Service. Mt. Britton Tower was built by the Civilian Conservation Corps in 1937 and is listed on the National Register of Historic Places as one of the best-preserved CCC recreational towers in Puerto Rico.

Where the sources disagreeThe tower may be closed. Hike With Ryan reported on 21 August 2026 that the road to Mt. Britton Tower and the tower itself were closed for construction while the trail stayed open, and that the El Yunque Trail was open only to Los Picachos, with the route to the peak closed; a July 2026 TripAdvisor review reached the tower. The Forest Service alert and trail pages could not be opened during verification, so check them before you go. The PR-191 recreation corridor is open 8:00 to 17:00, first come first served with no reservation since August 2023, and the gate closes when the car count is reached; arrive before 8:00. The forest's hurricane damage is not fully repaired: Caimitillo is open only as a connector, and La Mina, Big Tree and Baño de Oro trails were listed closed.

Trail path

The line
you follow.

StartMt. Britton Trail trailhead, PR-9938 loop road near km 13.0 of PR-191FinishMt. Britton Trail trailheadDirectionUp to the tower, back the same way. Turn right at Forest Road 10 for the tower; straight or left leads toward El Yunque Peak.
  1. 01PR-9938 trailhead
  2. 02Sierra palm forest
  3. 03Two stream crossings
  4. 04Forest Road 10 junction
  5. 05Cloud forest
  6. 06Mt. Britton Tower

Route sections

01 · The Palm StairsTrailhead to the stream crossings
The paved path climbs at once through sierra palm, crossing two streams that run hard after rain. Moss on the cement makes footing the first thing to think about.02 · The Road CutStreams to Forest Road 10
The trail meets Forest Road 10, closed to public vehicles. Turn right and follow it a few hundred feet to where the trail resumes; this is also the road to El Yunque Peak.03 · The Cloud FloorForest Road 10 to the tower
Dwarf cloud forest, wind and mist. The stone tower built in 1937 stands at 941 m; on clear mornings the east coast, El Yunque Peak and Los Picachos are in view from its top.04 · The Wet DescentTower to trailhead
1.3 km of slick paving, downhill. Short enough to repeat; most runners double it with the Caimitillo or Baño Grande paths below.

Weather profile

What the sky
is likely to do.

Tropical rainforest weather. Rain on most days, heaviest from May to November, with hurricane season peaking in September. The trail is wet and slick regardless of forecast; cloud sits on the tower most afternoons.

Season & timing

Managed seasonOpen every day 8:00 to 17:00 except Christmas, New Year's Day and Three Kings Day. PR-191 closes temporarily in heavy rain.Best windowDecember to April, at the 8:00 gate opening, for the driest paving and the best chance of a view from the tower.SurfaceCement and asphalt paving with gravelled sections, wet and moss-covered in places, crossing two streams and a short stretch of Forest Road 10DirectionUp to the tower, back the same way. Turn right at Forest Road 10 for the tower; straight or left leads toward El Yunque Peak.

Signature moments

What you will
remember afterwards.

01

Sierra palm closing over the paved path

02

The second stream crossing in spate

03

The tower appearing out of the mist

04

El Yunque Peak and the coast from the top

05

The road cut of Forest Road 10 in a break of sun

BUILT

1937

The tower at the top was built by the CCC in 1937

The National Park Service lists Mt. Britton Tower on the National Register as one of the best-preserved Civilian Conservation Corps structures in Puerto Rico. The trail is the way the CCC's own crews reached it.

Access & logistics

AccessFrom San Juan take PR-3 east to Río Grande, then PR-191 south into the forest. Pass the Palo Colorado area and turn right onto the PR-9938 loop road near km 13; the trailhead sign and parking are on the loop. Parking is limited; arrive before 8:00.PermitsNone. The PR-191 recreation corridor is free and first come, first served with no reservation. El Portal visitor centre charges an entry fee if you stop there.BookingsNone for the trail. Guided tours from San Juan handle parking and entry.WaterNone on the trail. Carry a bottle; the streams are not treated.FoodKiosks on PR-191 near El Portal and Palo Colorado; nothing on the trail.Mobile coveragePatchy inside the forest; do not rely on it above Palo Colorado.DurationPR Day Trips and Discovering Puerto Rico give 40 minutes one way; the Field Guide gives 1.5 to 2 hours round trip.

Key hazards

  • ▲Slick moss-covered paving
  • ▲Flash rises on the stream crossings
  • ▲Hurricane-season closures of PR-191
  • ▲Heat and humidity on the climb
  • ▲Gate closure at 17:00 with no exit after
  • ▲Construction closures at the tower

SafetyOrientation only. Always use current official maps, alerts and safety guidance. Check the Forest Service alerts page, wear shoes with grip on wet cement, carry water, and be back at the gate before 17:00.

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Official sources

Last verified 2026-09-16 · Record CETC-RUN-067 · Orientation only. Always use current official maps, alerts and safety guidance.

Photograph: Šarūnas Burdulis · CC BY-SA 2.0