The Lisbon Falls installation was designed by local architect Marcelo Dantas to enhance the experience of visitors to the fountain, which was completed in 1948 to celebrate the supply of water to the eastern part of the Portuguese capital.
"The structure is presented as an idea of transition to another reality," said the architect. "[It is] for the rediscovery of a known place, now experienced in a more complete way, covering all the senses of our body, in an experience that is meant to be total."
The temporary structure extends from a public plaza at the top of the Alameda Dom Afonso Henriques park into the fountain. It has a structure of timber battens, but is clad in panels of oriented strand board – an engineered material made from wood particles.
This material is often chosen for temporary installations, because it is cheap and easy to source, but also because of its variegated surface. Other recent examples of its use include a hilltop camera obscura and a seaside temple.
A long ramp stretches from the paved plaza over some short steps and enters a corridor that ascends gradually over the pool towards the fountain's upper level.
As the floor rises, the height of the walls decreases until visitors emerge above them and are treated to a panoramic view of the surroundings.
Where the walkway reaches the fountain's upper level it splits into two branches, with one branch continuing towards the cascading waterfalls, which plummet past sculptures of nymphs by early 20th-century sculptor Maximiano Alves.
The proximity of the water causes spray to rain down on the visitors, who can choose to stay dry by donning black waterproof capes when they enter the installation.
The other branch extends along the opposite side of the central statue of Tagus – this one by sculptor Diogo de Macedo – and brings visitors close to the streams of water projecting from the sculptures on either side.
This section of the walkway culminates in a transparent panel, intended to create the illusion that there is nothing between the floor and the water below.
At the start of a film presenting the project, the installation is described as a "photo opportunity" and an "urban cooling device" – which demonstrates the various ways it can be perceived and experienced.
"The choreographies generated in this scenario are spontaneous and diverse," Dantas added. "Acts of discovery, contemplation, surprise – but above all, actions from the willingness to share the experience."
The project is supported by the city municipality and construction was completed by Portuguese contractor Eurostand.
Photography and movie are by the architect.