It seems like something out of an elven fantasy novel: a hidden home with entry requiring a descent into the depths of terra firma. Serenely buried in the knolls of Portugal’s Alentejo region, Casa na Terra, a three-bedroom retreat, is one of the most unique offerings on the European vacation rental market.

Meaning “house in the earth,” the home’s name is extremely fitting, as the structure is organically camouflaged into a field of waving grasses and just a stone’s throw from the waters of Alqueva — Europe’s largest manmade lake.

The secret dwelling is the latest to be acquired by the Silent Living rental property group, a company dedicated to “the search for happiness and fulfillment” by providing patrons “a feeling of home.” According to its website, Casa na Terra fits instinctively within its carefully-curated portfolio as “the house honors very deeply its natural surroundings, finding shelter in the land itself.”

Designed by Lison-born architect Manuel Aires Mateus, the underground hideaway is an ArchDaily “Building of the Year 2020” award winner.

Aires Mateus is a graduate of the Faculty of Architecture at the University of Lisbon. He and brother Francisco founded the firm Aires Mateus in 1988 and have gone on to create a prolific body of work, earning both national and international honors along the way.

For this construction, the firm notes that “faced with the boundless extents of the Alqueva lake, the house require[d] a center: a protected courtyard embracing the water.” Indeed, the only feature visible from the lake is this focal piece, with the carved-out dome perched neatly over the concealed interior. The courtyard also opens into separate kitchen and living spaces that connect to the three en suite bedrooms via zig-zagging hallways. Each bedroom in turn opens onto its own “patio,” a circular air well painted in brilliant white to reflect light from above.

“The house is located in an area where construction is not allowed,” adds Aires Mateus. “Our ecological responsibility was also to make the house disappear into the landscape.”

Most of the bunker-like structure was built using concrete, while the interior finishes and furniture continue the theme of blending in with the surrounding environment. Aires Mateus says this minimalist-yet-inviting vibe was inspired by the notion of silence, incorporating elements like natural wood paneling, sheets of floor-to-ceiling mirrors, and built-in cabinets that are barely discernable from the rest of the wall to elevate that enveloping sensation of quiet. Rattan sofas and warm wood chairs soften the bare concrete surroundings. Even the hand-tied leather straps that serve as kitchen door handles conform to the voiceless flow of the house.

“In this case, the interior design and the architecture is not something to be seen, only to be felt,” Manuel explains.

Casa na Terra rates begin at €350 in the off-season, with a minimum stay of three nights. In the high season of June to September, seven-night reservations are required, with rates starting at €600. Breakfast and daily cleaning are included, and regardless of group size, the home is exclusively reserved for each booking party.

Aires Mateus has worked with Silent Living before, having renovated the 18th-century Santa Clara 1728, a stunning six-room hotel in Lisbon’s seven hills district.