Portuguese architects Álvaro Siza and Eduardo Souto de Moura have created a pair of installations in the Giardino delle Vergini for the Venice Architecture Biennale (+ slideshow).

Siza, who was this year awarded the Golden Lion for Lifetime Achievement, has installed a series of bright red walls amongst the trees and plants of the garden, while Souto de Moura has created a sandy-coloured structure that frames views over the waters of the Arsenale.

Angled slices provide windows in the walls of Souto de Moura's piece and Siza's features a cantilevered canopy that shades visitors as they leave.

Landscape designer Piet Oudolf designed the surrounding gardens for the 2010 biennale and returned this year to maintain them.

The Venice Architecture Biennale opened to the public this week and will run until 25 November.

Click here to see more projects by Siza, or here to see architecture by Souto de Moura.

See all our stories about the Venice Architecture Biennale 2012 »

Here's some more information from the exhibition:

Siza's piece accompanies and complements the installation by his long-time collaborator Eduardo Souto de Moura.

If the latter considers the choreography of views as an area of architectural enquiry, Siza's evokes the intimate bodily scale of the streets of Venice, and frames and makes new settings for the trees and planting of the Giardino delle Vergini.

Souto de Moura's piece, looking out across the water, creates both a gateway to the gardens, and directs views across the waters of the Arsenale.

The piece is intended as a reflection on the composition of facades and windows, while interpreting the surroundings of the garden and water.

Souto de Moura says "Geography become how we want it to be and not as it has to be. This is the great leap of the modern movement, and a result of postmodernism."

Siza was awarded the Golden Lion for Lifetime Achievement at this year's International Architecture Exhibition by La Biennale di Venezia.