In most of the Muslim world, the dome and minaret signify the mosque, acting as symbols that transcend linguistic and cultural barriers. In Istanbul, with its haunting skyline of historic domes and towers, the association between these traditional forms and religion is especially strong. So Emre Arolat’s design strategy for the Sancaklar Mosque on the outskirts of the city challenged long-held assumptions and popular images. “We wanted to get rid of the form,” says Arolat, the 50-year-old Istanbul-based architect who set up his own firm with Gonca Paşolar in 2004, after working in his parents’ practice since 1987. His parents—Neşet and Şaziment—have since joined Emre Arolat Architects (EAA), keeping the business a family affair.

Though not known for religious buildings, Arolat had designed two housing projects in Izmir for the Sancaklar family, the developers whose nonprofit foundation commissioned the mosque. Set adjacent to new gated communities and overlooking Çekmece Lake, in a suburban area 15 miles west of Istanbul’s historic core, the project straddles the boundary between the man-made and the natural. Across the road sit neo-Mediterranean houses and a shopping mall one might find in southern California. In the other direction, open fields slope down to the lake. Dealing with this awkward edge condition drove much of the design process.

“We realized that if we adjusted the topography just a little, we could make the building a part of the land,” says Arolat. So he and his team inserted the 13,000-square-foot mosque in the side of the hill and erected a series of freestanding stone walls to buffer it from the adjacent road and parking lot. Leaving their cars, worshippers walk through one of two openings in a 4-foot-high, slate-clad wall and into a courtyard on the upper portion of the property. A canvas covering can be pulled along a steel pergola here to create a shaded space for funerals. The courtyard—partially paved with the same gray kayrak slate as the walls, though given a smooth finish—extends out to the lake, acting as an open terrace from which to enjoy the view.

From the street and the courtyard, the only enclosed structure visible is a rectangular minaret—also made of kayrak stone. To find the mosque proper, you need to walk down slate steps embedded in the grassy hillside, then go along a lower courtyard lined in the back with cascading water terraces flowing into a long reflecting pool. The sound of moving water helps block out any noise from the street, enveloping the outdoor space in a calming aural blanket.

On the north side of the courtyard, a long pavilion that serves as a library and meeting space seems to float above the reflecting pool. On the south, the mosque itself beckons quietly to worshippers—a poured-concrete slab roof emerging from the hillside to form a welcoming canopy and, at one end, a steeply raked curving stone wall, bulging mysteriously and looking a bit out of place. Women enter the prayer hall through a portal announced by a pair of concrete walls projecting out to the courtyard, while men walk along an outdoor corridor defined by a freestanding stone wall underneath the mosque’s gently sloped concrete canopy. Almost hidden and utterly simple, the main entry expresses a humility that goes to the core of the project.

Instead of looking to the soaring spaces and elaborate geometric ornamentation of Ottoman-era mosques, Arolat found inspiration in the Cave of Hira, in present-day Saudi Arabia, where the Prophet Muhammad received the first revelations of the Quran. “We wanted to get away from any sense of spectacle, and reach the essence of the ritual of prayer,” says the architect. The prayer hall is a long 700-square-foot open space with plain gray carpeting; one of its main walls is surfaced with the ever-present slate, and the other is made of poured concrete. These facing walls slope almost imperceptibly in the same direction, adding a subtle motion that echoes angled bodies bowing in devotion. At one of the short ends of the hall, a perforated metal screen separates women from men, while at the other, a glass wall painted black on the back reflects the image of the space and the worshippers in it. A piece of modern calligraphy by Mehmed Özçay glows from the black wall, its bold letters done in clear glass and lit from behind.

Swirling above the sanctuary, a vortex of stepped concrete layers forms the ceiling. Shaped like contour lines on a topographic map, the ceiling recalls both a cave and a shallow dome, but in an abstract way. To erect the complex ceiling, the contractor used hundreds of CNC-milled wood forms for the poured concrete and attached it to the rest of the building’s concrete frame with a set of beams running above the prayer hall.

Eschewing decoration other than the roughly textured slate and the smooth concrete imprinted with the grain of its wood formwork, the architects at EAA used daylight to add drama to the interiors. The boldest example of this is the narrow skylight running above and illuminating the prayer hall’s south wall, or qiblah, which faces Mecca. The concrete beams supporting the sanctuary ceiling run below this skylight, separating the flow of light into shafts at certain times of the day.

At most mosques, worshippers leave their shoes at the entrance. But here, Arolat got the footwear out of sight by tucking shoe shelves behind the curving stone wall that bulges out toward the lower courtyard. It may be a small move, but it’s indicative of a larger effort to use minimalism to shape a contemplative place. Ali Elmaci, the imam of the mosque, appreciates the architect’s effort to hone the building to its essentials. “There are no distractions to the worshippers,” says the imam. “You have a closer, more peaceful relationship with the Creator.”