Swiss architecture studio Herzog & de Meuron has revealed an "optical illusion" infinity pool at Italy's Lake Como made from prefabricated steel and set against a backdrop of historic colonnades.

Located in the village of Blevio, the pool is part of a larger development by Herzog & de Meuron for the Mandarin Oriental Lago di Como resort.

This saw the studio reconceptualise the existing pool area and update the resort's indoor spa and reception.

According to Herzog & de Meuron, the infinity pool was designed to merge with the lake's water to create "a kind of optical illusion" – enhanced by the reflectiveness of the pool's glossy steel exterior.

"The new floating pool is designed to blend into the waters when viewed from the lake, and to reveal as much as possible from the historic vaulted colonnade," the studio said.

"Earlier infills in glass and steel are removed and the historic vaults are opened and activated," Herzog & de Meuron studio partner Ascan Mergenthaler told Dezeen.

The studio provided access to the pool and decking via a ramp leading from a newly established bar and dining area that extends from the structure's arched colonnade.

Made from prefabricated steel, the 40-metre-long pool's engineered form was designed to reduce wave impact. It is attached on one side to a wooden terrace hosting sun beds and parasols.

Cardoso sandstone, chosen for its likeness to the colours of the lake, was used for the pool's inner lining.

Inside the spa building next to the pool, Herzog & de Meuron focused on drawing daylight into the existing spa areas – which comprise a wet spa and a dry spa – and establishing new visible connections to the outside.

"While the pool area has been fully re-conceptualized, the wet and dry spa and reception areas have been improved while maintaining existing features that have not yet exhausted their usable lifespan," the studio said.

"A main focus is the introduction of natural daylight into all three areas of the spa, and the establishment of multiple visible connections with the surrounding landscape."

In the dry spa, a circular skylight was carved into the existing ceiling to draw sunlight into the below-ground space, while a more than four-metre-wide arched window was inserted into the wet spa's existing retaining wall.

Herzog & de Meuron also added a series of windows outlined by slim wooden frames to the reception area, complementing a row of smaller, existing openings.

The wet spa, hosting an existing sauna, steam room and indoor pool, was updated with a new vaulted ceiling made from stucco and lined with glass tiles, while the space's existing stone floor was repaired.

Here, the architects chose dark wood and neutral tones to create calming interiors that have been decorated with wood-framed vitrines, patterned textile wall panels and terrazzo floors that draw on motifs from the existing spaces.

While the spa is now open to guests, Herzog & de Meuron continues to work on the project.

"Future interventions and additions are currently conceptualised which will further strengthen the resort character of the existing property and form even tighter ties with the surrounding nature and villages." Mergenthaler said.

Other projects recently unveiled by Herzog & de Meuron include a giant cube proposed for archive storage for three museums in Seoul and a brick building for London's Royal College of Art.

The photography is by Robert Rieger.

Project credits: 

Partners: Jacques Herzog, Pierre de Meuron, Ascan Mergenthaler, Andreas Fries
Project team: Martin Krapp (Project director), Alessandro Farina (Project manager), Silvia Carrara, Monica Gaspar Bonilla, Riccardo Orsini, Francisca Soares de Moura
Design consultant: Herzog & de Meuron Basel
General planning: Lombardini22
Floating pool expert: Bluet, Floating Solution
Lighting consulting: Isometrix Lighting & Design
Pool construction: Bluet
F&B construction: Nove Consulting
Natural stone works: Vallmar
General contractor: L.a. Restyling S.r.l.
Furnishing & internal wood works: Ramiro s.r.l.
Furnishing: Hop Copper Studio
Internal surface treatments of wet spa: Sicis s.r.l.
Wallcovering: Rubelli S.P.A.
Upholstery and wallcovering installation: Ci.ti.ell
Lighting fixtures: L Gomiero
Internal wood doors and windows: D-Fabrics
Internal floor finishes (Terrazzo): AM Top Boden Gmbh