Uniting Sacred and Secular: Two Green Cathedrals of Europe

Cathedral construction was a major engine of medieval Europe. Does a new approach to this historical architecture hold new possibilities?

Giuliano Mauri, La Cattedrale Vegetale, Bergamo, Italy
Giuliano Mauri, La Cattedrale Vegetale, Bergamo, Italy

A few minutes ago every tree was excited, bowing to the roaring storm, waving, swirling, tossing their branches in glorious enthusiasm like worship. But though to the outer ear these trees are now silent, their songs never cease. Every hidden cell is throbbing with music and life, every fiber thrilling like harp strings, while incense is ever flowing from the balsam bells and leaves. No wonder the hills and groves were God’s first temples, and the more they are cut down and hewn into cathedrals and churches, the farther off and dimmer seems the Lord himself.

John Muir

Giuliano-Mauri-cattedrale-vegetale-cathedrale-vegetale-8 Giuliano-Mauri-cattedrale-vegetale-cathedrale-vegetale-7

The Cattedrale Vegetale, or Cathedral of Vegetation, stands at the foot of Mount Arera, near the Italian city of Bergamo. Designed by land artist Giuliano Mauri and completed by his son after the master’s death in 2009, the structure is composed of 42 beech trees. For now, the young trees are supported by columns constructed from fir trunks and chestnut and hazelnut branches. This frame is slowly rotting away as the trees grow. Much like the vaulted stone ceilings of a medieval cathedral, a canopy is slowly forming as the treetops bow toward one another. Five aisles lie between the rows of beech, which are staggered in height.


The Cathedral of Vegetation serves as a memorial to the work of an artist who created things that were usually short lived and subject to decay. Like any cathedral, it stands as a testament to its builder and his devotion, but this one enlists the aid of nature rather than merely subjugating and copying it. It returns to nature as a place close to creative energy and God. Mauri chose to allow people to share that energy by making the cathedral a place open to the community and visitors for worship, prayer and meditation.



Over 90 feet long and almost 80 feet wide, the grove of trees will reach into the skies for many seasons and years to come.





Very different from the old city of Bergamo, the master planned city of Almere is the newest city in the Netherlands, sitting on a tract of land reclaimed from Lake IJsselmeer between 1959 and 1968. This piece of land is referred to as a polder, a low lying area surrounded by manually operated dikes. In 1976, the first house was completed. The community was looking for an artistic concept that would make Almere unique. Marinus Boezem created De Groene Kathedraal, or The Green Cathedral.

De Groene Kathedraal
De Groene Kathedraal

Boezem will tell you that his Green Cathedral has nothing to do with religion and that viewing it in such a fashion is one-sided. That being said, it can hardly be separated from echoes of medieval Christianity. You can read more about his vision in this fascinating interview from the Museum de Paviljoens in Almere.

Reims Cathedral
Reims Cathedral
Rheims Floorplan with aerial view of De Groene Kathedraal
Rheims Floorplan with aerial view of De Groene Cathedral

The structure is made of 178 Italian Poplars planted in a design that mimics the architecture of Reims Cathedral in France, open to the sky rather than enclosed with a stone vault. Whereas the original design was inspired by tree trunks and natural structures, Boezem’s creation seeks to return that stone design to nature. Boezem took hold of the cathedral as a logo, the starting point of the new city. The image has roots in both sacred and secular space. Like Mauri’s structure, people of various faiths and walks of life do come to the cathedral to pray, meditate and worship, but that wasn’t the reason Boezem built it.

Medieval cities cultivated cathedrals not only as places of worship, but as community projects that brought people together to work for a common goal, providing employment and fellowship. It took time to build one, sometimes centuries, and being a part of the process was to be part of something bigger than yourself. Today, there aren’t many things that take so much time and attention. The Green Cathedral may not take centuries to finish, but the poplars do mature over decades. It is estimated that the trees will reach their peak this year, reaching the height of thirty meters, just shy of 100 feet, after which they will begin to die. Italian Poplars are short lived trees, and barring the planting of new ones, this cathedral will begin to decay in little more than thirty years from its original planting.


In the forest nearby, you will see a second cathedral, this one a negative space made by the deliberate lack of trees, looking startlingly similar to a large keyhole. This structure will remain much longer, as if to do homage to the symbol of the cathedral and the open space it creates for the future. It may also be interpreted as the continuing influence of Christianity, an impression left on modern culture and on the hearts and minds of humans.


What strike me about Boezem and Mauri’s cathedrals are the permeability and sustainability of their structures. Modern man and modern religion suffer from a rigidity and adherence to habit which threatens the world around us and the core of life itself. We can choose a different way. We can make space and embrace possibility.


The Earth’s health is the only standard that is all-encompassing enough to overcome the ethnic, cultural, religious, and national tensions that are rending the world asunder. Only the Earth can become the central axis around which which world peace can be spun, for no religion is more compelling, no single nation larger, and no peoples older than the Earth itself. For that to happen, the collective human consciousness must expand enough so that our highest identification is as Earth-Humans.

―Ilchi Lee, Magos Dream: Meeting with the Soul of the Earth
All photos are used in accordance with Fair Use Policy for educational purposes.

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