Presa El Gasco – Las Rozas de Madrid, Spain - Atlas Obscura
Places near me Random place

AO Edited

Presa El Gasco

Las Rozas de Madrid, Spain

This 18th-century project to build the world's tallest gravity dam was never completed.  

View all photos
Presa El Gasco Ceperez5
Presa El Gasco Ceperez5
South side of the dam Luis Morato (Atlas Obscura User)
Structure of the collapsed central part above the Guadarrama river Luis Morato (Atlas Obscura User)
The wall in the south side Luis Morato (Atlas Obscura User)
Presa El Gasco
Presa El Gasco
View from the west side Luis Morato (Atlas Obscura User)
47
112
Top Places in Spain
Menhires Pola Paz
Menhires Pola Paz
A Coruña, Spain
Palau Dalmases
Barcelona, Spain
La Mola Lighthouse
Formentera, Spain
 See All

This impressive 173 foot (53 meters) tall structure is the most significant and intriguing remnant of an 18th-century plan gone wrong.

Presa El Gasco was designed to be the starting point for a waterway extending well over 400 miles (771 kilometers), and dropping over 2,000 feet to Lisbon. A partial collapse and financial problems put a stop to the project years after it was clear no significant shipping could have been supported with the available water supply.

Today, the area around Presa El Gasco is a natural enclave with beautiful vistas of the Sierra, a forested island among one of Madrid’s most exclusive suburbs.

A comfortable 90-minute hike will take visitors from Torrelodones to the actual site. Along the way and only partially hidden by vegetation, additional hints point to the long-gone days of construction such as small aqueducts to divert creeks, foundations of engineers’ quarters, and mounds of solidified lime. 

Know Before You Go

Once at the site, exert caution. Though the dam wall is seemingly solid and sturdy, it has received no significant maintenance in decades.

Atlas Obscura Trips

Flavors of Spain: A Culinary Adventure Through Catalonia

Barcelona to Costa Brava: Food, Wine & Culture.
Book Now
dams abandoned architecture
Nearby
Welcome to Fabulous Las Matas Sign
2.67 miles
Cementerio del Cristo (Cemetery of Christ)
7.59 miles
Silla de Felipe II (Phillip II’s Chair)
10.96 miles
Want to see fewer ads? Become a Member.
Near This Place
The sign.
Las Rozas de Madrid, Spain

Welcome to Fabulous Las Matas Sign

An ode to the famous Las Vegas signage.
Aerial view of the roundabout
Villanueva de la Cañada, Spain

Cementerio del Cristo (Cemetery of Christ)

This small cemetery and its chapel are located in the middle of a traffic circle.
"The seats"
San Lorenzo de El Escorial, Spain

Silla de Felipe II (Phillip II’s Chair)

According to tradition, King Phillip II supervised construction of the seat of his empire from this seat carved into rock.
Inside the library.
San Lorenzo de El Escorial, Spain

Royal Library of San Lorenzo de El Escorial

This influential Renaissance-era library was once the haunt of kings and monks.
Related Places
Hammam Lif, Tunisia

Abandoned Casino

This gem of Moorish architecture is slowly disintegrating along the coast of this charming town.
Jankowo, Poland

Walter Gropius's 1906 Spichlerz

A Bauhaus co-founder designed this quirky, abandoned granary.
Velha Goa, India

The Arch of Conception

One of the few surviving gates into Old Goa, the former capital of Portuguese India.
Bucharest, Romania

Solacula Inn

An abandoned pasta factory in the centre of Bucharest, once home to Bulgarian revolutionaries and a hub of crime.
In partnership with KAYAK

Plan Your Trip

From Around the Web