WHEN LOUIS KAHN began work on the Parliament complex in Dhaka in 1962, he included in his plan what would be one of the first and, for decades, the most important Modernist mosques in Bangladesh. A lofty cube, its corners girded by oversize hollow cylinders, the prayer hall, from a bird’s-eye view, extends into the moat surrounding the hulking, fortresslike Parliament complex at a slight angle, as though caught in a gentle tide. It disrupts the building’s near perfect symmetry only so that its mihrab could face precisely toward Mecca. Inside, it is a study in light and texture: Eight immense round windows bend around its corners, the continuations of their arcs spreading into the hollow columns like flying buttresses. Sunlight filters in through the open tops of the columns and flickers over the sculptural imperfections in each hand-cast concrete slab. Triangular squinches angle up from the corners, the beginnings of a dome that never materializes. Instead, Kahn placed his closest approximation of a dome, the most enduring symbol of Islamic architecture, over the floor of the neighboring assembly hall: a vaulted octagonal structure soaring 117 feet over a space dedicated to the mundane work of governance. While the assembly hall is grand, the mosque is introspective. Democracy, the building suggests, would become the state religion, fortified by a quiet, inclusive faith.

It would take 25 years for anyone in Bangladesh to build a religious space anywhere near as inventive. Under the military governments that mostly ran the country from 1975 to 1991, many major mosque projects were commissioned by rulers, says Ehsan Khan, 54, “so they were designed for political purposes and used a cheaper symbolic language.” Khan spent his early years in architecture at Islam’s firm. In 1996, shortly after Sheikh Hasina was elected to her first term as prime minister, the Bengali cultural ministry commissioned Khan to design a mausoleum for Hasina’s father, Bangladesh’s first president, Sheikh Mujibur Rahman. The architect surrounded the grave with a ring of perforated concrete, recalling the carved jali screens found around Sufi tombs and other Indo-Islamic structures, and crowned it with a concrete shell that borrows its shape not from typical mosque domes but from the bowed rooflines of traditional village houses. The mausoleum combined Modernist techniques — porous surfaces, bold geometries — with regional Muslim codes, but those innovations were likely only welcomed because the building was not, technically, a place for prayer. Despite that, Khan’s mausoleum suggested an architecture that could help define and express Bangladesh’s own religious aesthetic.

Then, in 2005, Kashef Mahboob Chowdhury, the now 48-year-old principal of his firm Urbana, received a commission from a rich Dhaka-based client to design a mosque in Chandgaon, a neighborhood at the northeastern edge of Chittagong, Bangladesh’s second-largest city. Completed two years later, the Chandgaon mosque is simpler and more abstract than Khan’s: a long, white rectangle suspended among bananas and palms, perforated by a low threshold that leads into a forecourt beneath an immense oculus. Glass doors open to a prayer hall capped, in Chowdhury’s only concession to tradition, by a small dome, split like a book in wedged glass. “[The patron] said he wanted a modern mosque, something that would bring the area forward,” Chowdhury says. “I wanted to go back to the beginnings of mosques.” For him, this meant stripping away ornament to uncover the building’s essential function as a shaded place for Muslims to pray. In reducing the mosque to its most fundamental elements, Chowdhury landed on something straight out of Bengal’s past: a basic pavilion, its every surface open to the voracious world. In 2012, the Dhaka-based architect Rafiq Azam took that premise a step further in his renovation of a family graveyard at a residential compound set among rice paddies in Bangladesh’s rural south. Azam raised the plot on a platform and set it off from the rest of the site with a wide, low staircase and a broad concrete threshold to represent “a line we can cross anytime” between the celestial and terrestrial worlds. Chowdhury and Azam adapted the fluidity of space that inspired the region’s early Modernists into the spiritual realm. And, in its own way, the Chandgaon mosque proved that the dichotomy between secular and religious architecture had always been false.