Located in Spain, Trufa is a vacation home by Ensamble Studio. The structure which means "truffle," was created by pouring concrete over hay stacks stacked and buried in local soil. Once the structure dried, the casing was removed and a cow, named Paulina, was brought in to eat the case inside, hollowing out the space over the course of a year.
A note from architect Anton García-Abri:
The Truffle is a piece of nature built with earth, full of air. A space within a stone that sits on the ground and blends with the territory. It camouflages, by emulating the processes of mineral formation in its structure, and integrates with the natural environment, complying with its laws.
We made a hole in the ground, piling up on its perimeter the topsoil removed, and we obtained a retaining dike without mechanical consistency. Then, we materialized the air building a volume with hay bales and flooded the space between the earth and the built air to solidify it. The poured mass concrete wrapped the air and protected itself with the ground. Time passed and we removed the earth discovering an amorphous mass.