Hot Spots, Hot Water
Geothermal springs offer respite in the Chilean desert and Patagonia.
By Jimena Martignoni
Two successful landscape architecture projects are located
on opposite ends of Chile: the Puritama Hot Springs (Termas de Puritama) and the Geometrical Hot Springs (Termas Geométricas). The sites of the two springs reflect
the landscape diversity of Chile: from the world’s driest desert, the Atacama
Desert in the north, to the exuberant woods and blue lakes of Patagonia in the
south, along the country’s approximately 2,700-mile length. However, there is a
dominant physical feature that extends that entire length, from the Bolivian
plateau to Tierra del Fuego, visually and geologically connecting many Chilean
landscapes: the Andes. As part of this mountain system, hot springs are
dispersed throughout the country.
The two hot springs projects are the work of one designer
who is highly respectful of local natural attributes. Germán del Sol is a
Chilean architect whose projects have involved landscape design. He has been
shifting his architect’s vision to become more open and inclusive, focusing on
site-specific design. After studying in Barcelona and working in the different
regions of Chile, he has become one of the country’s most recognized designers.
Del Sol’s design for the hot springs takes advantage of four natural features:
the northern desert, the southern lakes, the Andean mountains, and the
The thermal baths in the northern desert are an unexpected
gift much appreciated by locals and visitors: a subtle line of water and life
hidden in one of the driest places on Earth. Conversely, the thermal baths in
the southern woods are an overwhelming experience of water—a flowing river,
pools, steam, and, if one gets lucky, a refreshing rain in summer or a light
snow in winter.
The Puritama thermal baths are 21 miles from San Pedro de
Atacama, an oasis 8,000 feet above sea level created by the rainfall of the Bolivian
altiplano winter in the Atacama Desert. In the middle of a landscape of arid
mountains colored in red, ocher, and sepia (depending on the morning, noon, or
evening light), the town of San Pedro emerges as an isolated green node of
This city, first settled by the atacameños—a local farming culture—was conquered in 1425 by the
Incas and then by the Spaniards in 1535. While the Chilean community at large
does not have a completely mature environmental awareness yet, small towns like
this one are starting to take good care of their cultural and natural heritage.
The Puritama geothermal river flows along an almost
1,000-foot-deep crack carved in the rocky desert mountains, bubbling out as
springs at 86 to 92 degrees Fahrenheit. The name Puritama actually comes from puri,
which means water, and tama, which
When del Sol visited the site for the first time, it was
basically a 1,650-foot-long crack along which the river flowed and where the
riverbanks were covered with Andean pampas grass or cola de zorro (Cortaderia atacamensis), an ornamental native plant.
Along this linear natural system, some pools of hot water carved out by local
people in ancient times remain, along with two adobe buildings (kayankas) near the site’s entry point
that were constructed by the Incas when they conquered northern Chile.
This scene is what del Sol worked with after the land was
bought by the Atacama’s Explora Hotel. He proposed the Pueblo Atacameño Council
as the managing organization for running and taking care of the site.
Archaeologist Carlos Aldunate del Solar, director of the Pre-Columbian Museum
in Santiago, was the specialized consultant at the site who worked hand in hand
with del Sol.
The Puritama Thermal Springs make reference to the
atacameños culture with white-painted dressing rooms that echo the emblematic
white architecture of the town of San Pedro de Atacama. A wooden boardwalk
crosses the site about one foot above river level, allowing the grass
underneath to grow and giving visitors access to the different pools and
resting spots. When the boardwalk reaches the pools, it widens and creates
small terraces that face the water so people can sunbathe or just rest.
The eight pools were broadened, deepened, and partly covered
with stone walls. As a consequence of the drip irrigation system that was added
by the designer, the Andean pampas grasses now grow exuberantly in thick masses
that hide the stone structures, while their silver crests attract light and
create a mystical effect during certain times of the day.
Two minimalist-looking white box-shaped buildings stand
close to the main access, each of them offering a bathroom, a dressing room,
and a sauna. The same small collecting pool that feeds the irrigation system
provides running water.
The kayankas, or small Incan shelters, were restored and
rehabilitated as administration offices, and new straw roofs were added that
are reminiscent of the original construction materials.
Seen from the road that goes down the mountain slopes, the
site is presented as a whole, a green strip of tall grasses crowned by
white-silver crests and crossed by a long, narrow path that gets lost in the
vast arid landscape. The path, painted dark red, creates a major color contrast
with the grasses and with the sepia and gray hues of the enclosing mountains.
The site’s parking area is on a plateau at the same level as
the site itself. From here, visitors leave their cars and step onto the
boardwalk entry point surrounded by the tall Andean pampas grass, which screens
each turn the boardwalk makes. Visitors literally discover the pools and the
terraces shaped by the boardwalk while walking it. Some terraces are completely
surrounded by the Andean grasses, making them isolated, intimate spots from
which the view is reduced to the blue of the sky and the surrounding mountains.
Others are framed by the grasses in a more open manner, creating wider vistas
of the site.
Inside the pools the water is warm, the small waterfalls
that most of them have act as natural massage showers, and the sun feels strong
on your face. (Solar radiation in Atacama is really high, and many
white-skinned Americans and Europeans go back home at the end of the day
completely relaxed but badly sunburned if they forgot their sunscreen!)
Accessing the site requires a $10 entrance fee, which
includes the use of all amenities for the day. However, the atacameños people,
who had historically “owned” the springs, have free admission to these thermal
The construction of Puritama took no more than three months,
but the installation of the drip irrigation system and the restoration of the
Incan shelters, which were done in phases, delayed the finish. The site was
opened to the public in 2000.
Both the design and construction were a 100 percent in situ
process in which del Sol, together with other people from his office, worked at
the site marking the boardwalk’s exact placement with ropes and then
translating the design onto paper.
In San Pedro de Atacama, farming areas take turns being
watered; common cisterns that are part of a system of channels fed by local
rivers provide water on a very rigid schedule that everyone respects. The urban
area has running water only during the day. In contrast, the Andean woods of
Patagonia or “area of the lakes,” as it’s called in Chile, benefits from a
great deal of water—as much from an ecological perspective as from a visual
These thermal baths are located 62 miles from Pucón, one of
the most beautiful Patagonian cities in Chile, situated by the still-active
Volcano Villarrica. From Pucón two different roads can be taken, one of them
only possible with a four-wheel-drive vehicle, both going up to 6,500 feet,
where the springs flow.
Del Sol discovered the site after a 15-year search following
Spaniards’ chronicles that described mystical sites with geothermal waters.
The site is a 1,800-foot-long stony canyon. He hardly
noticed the river waters that run through this linear canyon when he first
surveyed the site, because the length of it was covered with dirt, stones, and
logs. The land belonged to a private logging hacienda, one of the few remaining
inside the 156,000-acre Villarrica National Park.
In 2002, del Sol rented the place with a 30-year lease and
began clearing it out, a process that took a whole year and filled more than
100 trucks with trash and dirt. As a result, the river started flowing faster
and moving an average of five gallons of water per second, when previously it
moved fewer than one.
To accomplish a sound environmental excavation, del Sol
worked with a team of mine engineers, hydrologists, and geologists. To find the
exact location of the springs they used thermometers that indicated the spots
where the land was hotter. Digging carefully at those locations, they marked 60
hot water pools where the temperature is approximately 185 degrees Fahrenheit.
The Geometrical Thermal Springs owe their name to the
geometrical configuration of the site, which is set against the luxuriant
organic lines of the wilderness setting. “I wanted to tame nature, but at the
same time emphasize it,” says del Sol. “This is a space framed by a wild
environment that I intended to make livable, but I also meant to stress
One of the biggest differences from Puritama was that when
the conceptual layout started taking form, no pools existed, and del Sol knew
he had to design them from scratch. Referring to the intentional contrast of
the new design with traditional natural forms, he says, “Designing them as if
they had been naturally shaped made no sense, so that’s when I decided to apply
geometry and lay them out as geometrical pools, surrounded by geometrical
To take better advantage of the strong natural setting, the
geometrical pools are placed on both sides of the central boardwalk, facing the
canyon’s walls. Concavities in the canyon walls outline the pools’ inner sides.
Del Sol intended to create a self-contained space accessed
by a “round-trip” circuit, with just one entrance through which people enter and
leave the site. The space is therefore physically contained not only by the
canyon’s stony walls, which are impossible to climb, but also by the man-made
structure of the boardwalk.
The humidity generated by the water and steam has led to the
walls being covered with lush green vegetation native to the area. Large ferns,
mosses, and philodendron species wrap the stone, crowned by the typical coihue
forest (Nothofagus dombeyii or
southern beech) of Patagonia.
Del Sol uses old Mapuche (Patagonian aboriginal groups)
techniques to regulate temperature and to channel the water using gravity.
“Routing the water all through the site with a typical sealed piping system
would not match the site’s concept and, even worse, would turn into a problem
for cleaning, maintenance, and heat loss,” says del Sol. “What is inherent to
hot springs is that they keep the heat while openly flowing.”
The thermal water is collected from every one of the 60
springs by polypropylene tubes that feed to a main wooden open channel that
runs right underneath the central boardwalk, all along the site. This keeps the
boardwalk warm even during cold days, and a light steam is constantly rising
into the air.
The flowing water in the main central channel, with a
temperature up to 185 degrees Fahrenheit, is circulated to five retention pools
through wooden closed distributors. Once the reposing water there cools down to
approximately 102 degrees, it’s sent through the same kind of channels to 12
The pools are cleaned every three days to maintain them and
prevent health problems. They are emptied at four in the morning and cannot be
used until the afternoon, when the temperature is appropriate for bathing, so
the cleaning schedule is rotated to keep some pools in use while others are
The central boardwalk runs along the entire site following
the natural topography, making some angular turns that make the walk and the
scene more dramatic. As in Puritama, the boardwalk is painted red, but here the
grass-roofed dressing rooms are also painted in that color. To one side of the
boardwalk, the cold river water flows constantly without mixing with the water
of the hot springs. After bathing in the pools, visitors have the option of
going into the river.
At the Termas Geométricas, the experience of the site is one
of adventure, mystery, and literal fogginess. Just getting to the site involves
a long drive. Once there, visitors leave their cars and walk five minutes to
the entrance, where they are provided with towels and keys to lockers located
inside the dressing rooms. People walking up and down the boardwalk, bathing,
or chatting; the steam filling up the environment; the green fully covering the
canyon walls and contrasting with the red of the central boardwalk; and the
super hot water of the pools all create a fantastic experience for the senses.
Even though the long ride through the Patagonian woods and
towns is well worth the experience, one could argue that accessibility to both
sites is limited to those who have a car or can afford a ride up there, but
generally speaking, people gather in groups and find ways to make the trip less
expensive. In February, during the Chilean summer break, the number of visitors
to the Geometrical Thermal Springs can reach up to 280 persons per day; the
rest of the year the number goes down to an average of 50.
After the long ride it takes to get to these sites, visitors
perceive them almost as “hidden treasures.” But they shouldn’t be, for water
is, literally, a precious source of life. The issue that arises here is to what
extent these sites should be more accessible and how local governments could
become more involved in this kind of development in Latin America.
Jimena Martignoni is
an independent landscape architect and researcher in Buenos Aires, Argentina.
The Puritama Thermal Springs have received several awards,
including an honorable mention at the 12th Biennial of Architecture of Quito,
Ecuador, in November 2000; a gold medal in 2001 at the International
Architecture Biennial of Miami; and the 2001 Arup World Architecture Award for
Best Project in Central/ South America.
The Geometrical Thermal Springs earned first place in the
14th Architecture Biennial of Santiago, Chile, in November 2004, and took the
Grand Prix of the Landscape Architecture Look from Home exhibition and
competition held at Dom na Brestskoy in Moscow in October 2005.
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