GEOSITES
WHAT ARE GEOSITES?
A geosite It is a geological point of special scientific, educational, landscape or heritage relevance, whose preservation allows us to interpret the evolution of the territory and its natural processes.
Given their relevance, geosites are used as natural laboratories, open-air classrooms, or tourist landmarks that enable local sustainable development.
Not all geological points of interest are geosites. Scroll to the bottom of the page to learn about other emblematic landmarks of the Maule Andes.
Discover the location of the 20 geosites of the Pillanmapu Geopark on our interactive map:
Discover the most emblematic geosites of the Pillanmapu UNESCO Candidate Geopark
Geosite 3 - Tarn Laguna El Alto
Located within the Altos de Lircay National Reserve, Laguna El Alto is a body of water of glacial origin Located within a cirque perfectly sculpted by ice during the Pleistocene, the lagoon is surrounded by the steep walls of the Cerro Peine mountain range. It sits in a depression carved by ancient glaciers and fed today by snowmelt and pluvio-nival flow. Its landscape combines the deep blue of the lagoon with the steep slopes and high Andean vegetation of the Maule region, which adds verdant hues to the surroundings. It is one of the most emblematic geosites of the Altos de Lircay National Reserve, recognized for both its scenic beauty and scientific value, and is in a state of pristine conservation, also associated with biological and archaeological elements present in the area.
Tarn's definition: Tarns are lakes that form in glacial cirques, that is, in the amphitheater-shaped hollows left by glaciers after they retreat.
Geosite 4 - Ignimbrite The Brickwork
Located within the Altos de Lircay National Reserve, El Enladrillado is a large volcanic plateau Formed by ancient Pleistocene eruptions, whose ignimbrite deposit was leveled into an almost perfect platform. Its surface is covered with large polygonal blocks that resemble a natural cobblestone, which were formed at the moment when cooled and contracted the burning material. It originally covered a larger area, but erosion of the glaciers It left only the platforms we see today.
Located at an altitude of over 2,180 meters, this geosite offers exceptional views of the Descabezados Volcanic Group, the glacial traces that shaped the plateau, and the tectonic folds of the mountain range. In addition to its scientific value, El Enladrillado is an iconic viewpoint within the National Reserve and a meeting point for geology, archaeology, and the flora and fauna of the high Andean steppe of Maule.
Definition of Ignimbrite: An ignimbrite is a rock formed by ancient explosive eruptions, when fiery clouds of ash, gases, and volcanic fragments rush down the slopes at high speed. As it cools, all this material fuses together, forming extensive layers of light, porous rock, which we can see today in the walls, ravines, and terraces of the mountain range.
Geosite 6 - Lava from the Quizapu Volcano
The lava flow from the 1846-1847 eruption of Quizapu volcano is a magnificent example of how lava flows can fill valleys and alter landscapes: with an estimated volume of approximately 5 km³, a thickness that varies between 25 and 210 meters and a covered area of approximately 50.4 km², This enormous flow moved from the Quizapu cone towards its slopes and valleys.
Geosite 7 - Descabezado Grande Stratovolcano
The Big Headless One is an imposing stratovolcano which dominates the Maule mountain range, recognized by its distinctive flattened summit, its wide crater, and its eruptive history linked to the Descabezados Volcanic Group. Its activity, marked by explosive and effusive episodes, has shaped a landscape of lava flows, domes, and pyroclastic deposits that extend for several kilometers. From its slopes, clear evidence can be observed of ancient glaciers that carved valleys and cirques around the volcanic edifice, revealing the interaction between volcanism and glaciation. Due to its magnitude, its geodiversity, and its role in the volcanic evolution of the Maule region, The Descabezado Grande is one of the most emblematic and spectacular geosites of the Pillanmapu Geopark.
Definition of Stratovolcano: A stratovolcano is a large, conical volcano formed by the successive accumulation of layers (or strata) of lava, ash, and volcanic fragments. These volcanoes typically have steep slopes and can produce both effusive and explosive eruptions, making them common in subduction zones such as the Andes Mountains.
Geosite 9 - Quizapu Volcano Crater
The Quizapu crater is one of the most emblematic eruptive centers of the Maule Andes, marked by two historical eruptions that reflect the duality of Andean volcanism. In 1846–1847, the volcano developed a effusive eruption which emitted a huge flow of dacitic lava, considered one of the most voluminous ever recorded in Chile. Decades later, in 1932, Quizapu starred in a explosive eruption of Plinian scale, with an eruptive column that reached tens of kilometers in height and dispersed ash across the continent. This contrast—a monumental lava flow followed by a colossal explosion—makes the Quizapu crater an exceptional natural laboratory for understanding how a single volcanic system can oscillate between effusive and explosive behaviors over time.
Explosive vs. effusive eruption: An explosive eruption occurs when magma is violently expelled in the form of ash and gases, while an effusive eruption corresponds to the quiet release of lava that flows over the ground.
Geosite 10 - Los Hornitos Cones
Los Hornitos correspond to a set of small monogenetic cones where magma emerged in a localized manner creating well-defined conical mounds and craters. These structures, associated with the recent volcanism of the Descabezado Grande – Quizapu – Cerro Azul complex, allow us to observe how magma can rise through fissures and quickly solidify into small, now-inactive volcanoes. Their landscape, marked by minor lava flows, pyroclastic deposits, and symmetrical slopes, provides a direct window into the most recent eruptive dynamics of the Maule mountain range and complements the larger volcanic record visible from this area.
Definition of monogenetic cone: A small volcano formed by a single eruption or a very brief eruptive event, where magma rises only once to create a conical mound of ash, scoria, and volcanic fragments.
Geosite 13 - Médano Geothermal System
The Médano geothermal system is a large area where the heat from the mountain range causes water and vapors to rise from the depths, coloring the hills with reddish, orange and yellow tones. This natural heat gives rise to the Médano Hot Springs already the Steam from the Sand Dune, where hot water and steam emerge from the rocks, forming pools and small natural saunas. It's an ideal place to understand how the Earth's internal energy works and, at the same time, to enjoy a unique landscape in the Maule River valley, accompanied by the area's typical flora and fauna.
Definition of a geothermal system: A geothermal system is a place where the Earth's heat warms underground waters that rise to the surface as hot springs or steam.
Geosite 14 - Columnar Disjunctions of La Cárcel
The Prison is an impressive columnar lava wall located on the south bank of the Maule River, at the entrance to the Valley of the Condors. Its perfectly vertical columns, formed by the contraction and fracturing of ancient lava flows, create an almost sculptural geometric landscape that is now widely enjoyed by the climbing community. Located near other landmarks such as the Inverted Waterfall and the Maule Waterfall, the surrounding area combines grayish-toned rocky slopes with Andean scrubland. This geosite stands out for its natural beauty, its educational value in understanding how columnar jointing structures form, and its cultural and recreational role within the valley.
Definition of columnar disjunction: pattern of natural columns that forms when a lava flow cools and contracts, fracturing into geometric, usually hexagonal, figures that create almost perfect pillar walls.
Geosite 15 - Inverted Waterfall
The Inverted Waterfall is a waterfall where the wind slows the fall and completely reverses it. This occurs because the waterfall plunges directly into the main valley. Thus, when the wind is channeled strongly in the right direction, it strikes the column of water and causes it to rise like an inverted feather. The waterfall, in turn, exists thanks to the stepped topography of the area, shaped by ancient civilizations. lava flows that formed plateaus and vertical walls at different levels, the same ones that are used for climbing in the Valley of the Condors.
Geosite 16 - Valley of the Condors
The Valley of the Condors is made up of large plateaus of lava that filled the valley and whose edges have fractured and collapsed slowly over time, giving rise to the imposing vertical walls that characterize the area today. The natural fractures that divide the lava into elongated columns (like those of La Cárcel, but less perfect) allow some of them to tilt and fall forward, exposing straight, towering walls that appear hand-cut. Thanks to these volcanic walls, unique in the Maule mountain range, the valley has become one of the most important and renowned climbing destinations in Chile, attracting athletes from all over the world.
Geosite 17 - White Monks Tufa
The Valley of the Condors is made up of large plateaus of lava that filled the valley and whose edges have fractured and collapsed slowly over time, giving rise to the imposing vertical walls that characterize the area today. The natural fractures that divide the lava into elongated columns (like those of La Cárcel, but less perfect) allow some of them to tilt and fall forward, exposing straight, towering walls that appear hand-cut. Thanks to these volcanic walls, unique in the Maule mountain range, the valley has become one of the most important and renowned climbing destinations in Chile, attracting athletes from all over the world.
Geosite 19 - Laguna del Maule
Laguna del Maule is a highly monitored volcanic field whose magmatic system has been identified at about 5 km below the surface, where an expanding magma chamber has been driving a notable uplift of the terrain since 2007. Between 2007 and 2012 the area experienced uplift rates exceeding 20 cm/year, The subsidence has been sustained at hundreds of millimeters per year for consecutive years. This phenomenon, combined with persistent seismic swarms and the presence of more than 130 eruptive conduits, makes Laguna del Maule one of the most closely monitored volcanic sites in Chile. Its recent activity—uplift, deformation, and internal movements—demonstrates that the system remains in a state of reactivation, thus constituting both a first-rate geological heritage site and a key area for volcanic monitoring.
Definition of volcanic complex: A group of volcanoes, craters, domes, and fissures that share a common magmatic system and eruptive history. Rather than a single isolated volcano, the complex forms a "system" where different eruptive centers can become active at different times.
Geosite 20 - Campanario Volcano
The Campanario Volcano is an emblematic natural landmark of the Pehuenche Pass, a summit of more than 4,000 meters formed by a ancient stratovolcano that was deeply sculpted by the glaciers of the last ice age. Only the internal structure of the volcano survived from this last eruption, leaving exposed vertical walls of volcanic rock. The reddish and blackish tones of its andesitic lavas contrast with the whitish deposits that surround it, creating one of the most emblematic volcanic landscapes of the Geopark.
OTHER EMBLEMATIC SITES
Not all geological landmarks are necessarily geosites, but they still form an essential part of the identity of the Pillanmapu Geopark. This section brings together those landmarks that, while not geosites, are equally significant for those who visit, research, and live in the Maule mountain range.
Discover other iconic sites of the Pillanmapu Geopark:
