The expansive roof of this seaside house in Cádiz, Spain, by Alberto Campo Baeza stretches out towards the shoreline like a flattened extension of the rugged terrain (+ slideshow).

VT House, also known as "house of the infinite", was conceived by Spanish architect Alberto Campo Baeza first and foremost as a piece of landscape architecture, with its architectural elements sunken underneath.

"We have erected a house as if it were a jetty facing out to sea," said the architect. "On this resoundingly horizontal plane, bare and denuded, we face out to the distant horizon."

The building comprises a bulky rectangular box, 20 metres wide and 36 metres deep, although the extensive upper terrace gives the impression that the structure is much larger.

Two storeys are housed beneath the rooftop plane. The front half of these floors emerges from the terrain to meet the beach, while the rear half was created by excavating 12 metres into the rock.

The entire structure was built from travertine stone, which Campo Baeza describes as a reference to Cádiz's Roman heritage.

"The Romans were there a handful of centuries ago," he explained. "Bolonia, the ruins of the Roman fishing factories where they produced garum and built temples to their gods, is just a stone's throw away."

"In their honour we have built our house, like an acropolis in stone, in Roman travertine," he added.

A monumental wall marks the boundary line between the landscape and the terrace. Beyond this, a swimming pool is sunken into the surface, while a grand staircase leads down inside the house.

The upper level of the building contains rooms dedicated to socialising, including a living room with a circular skylight overhead and a covered balcony in front. This leads through to a simple kitchen with a large dining area.

The lowest level accommodates a series of en-suite bedrooms, positioned on either side of a communal central space that leads straight out to the beach.

Campo Baeza, whose past projects include a walled house for a poet and a hilltop home with a bulky concrete structure, describes the building as " the most radical house we have ever made".

"On a marvellous place like a piece of earthly paradise, at Cádiz, we have built an infinite plane facing the infinite sea," he said.

Photography is by Javier Callejas.