In the south of the island of Tenerife, near the town of Güimar, there are dark and narrow tunnels almost 16 km long, steep cliffs about 1 km high, and abysses — everything to interest adventurers and experienced travelers. This place is not for the faint hearted! It is forbidden to walk on it, as it is extremely dangerous. However, curiosity kept me on my toes, I visited it and decided to share this unique find with you. The trail is called Mil Ventanas de Güimar, which means «1000 windows of Güimar» in Spanish.
How Las Ventanas de Güimar came to be
There are no legends or supernatural stories tied to this place. The tunnels are an engineering project from the early 20th century, dug horizontally into the mountainside as part of a water canal meant to channel resources from the highlands down to the Valle de Güimar.
The galleries were carved by hand, using picks and shovels. The openings in the rock served two practical purposes: they let in natural light along the long, dark passages, and they gave the workers a way to dispose of the stone debris produced while drilling. That is why the site is also known as Mil Ventanas de Güimar, literally «a thousand windows of Güimar».
The canal, however, never fulfilled its purpose. According to local accounts, the expected water flow was never found, and the infrastructure was left unused.
Route Mil Ventanas de Güimar
Some full-loop GPS tracks of the 1000 ventanas de Guimar register a total distance of 23.18 km and a positive elevation gain of 1,690 m, accumulated mostly during the approach and the descent back to the village. Plan around 3 hours just for the aqueduct section, plus the hike in and out.
The trail is unofficial and unmaintained. Slabs are broken, debris blocks parts of the channel, and the path often runs along the cliff edge. Vertigo is a serious risk: if you are uneasy with exposure, turn back.
Pack the following gear before starting the ventanas Guimar route: a tested headlamp with spare batteries for the unlit tunnels, a helmet to protect against the low tunnel ceilings, long trousers and long sleeves against scrub and rock, and a basic first aid kit. Check the steel safety cable at the start — it breaks before the first tunnel.
Just before that first tunnel, look for the upside-down excavator that fell here in 2005 (on the map).
Mil Ventanas de Güimar
After the seventh tunnel, the most beautiful part begins. The mountain forms a semicircle, and you will have an amazing view of the mountain valley, surrounded by steep cliffs with numerous openings — a thousand Güimar Windows.
How to get there
Most hikers start near the radio masts above Güimar, reached by the old TF-28 road from Arafo or Güimar town. Park on the dirt verge close to the antennas, where the trail drops south toward the Don Martín lookout and the Anocheza path. Parking on Google Maps.
The full walk is point-to-point, roughly 8 km between trailheads, so arrange a taxi pickup from Güimar town for the return. Download an offline Tenerife tunnel map before setting off: the path is unmaintained, signage is scarce, and mobile coverage drops inside the gullies.
What’s around?
History and engineering buffs will be interested in the abandoned hydroelectric plant that once supplied electricity to half of Guimar.
Paragliding enthusiasts will appreciate the slopes of Guimar, one of the first places in Tenerife where paragliding was practiced.
Ready for adventure, Las Ventanas de Güimar awaits you!
