The question of what awaits after death has obsessed humanity for millennia.

The Korean photographer Chanho Park’s fixation took root when he was 11 and his mother, who suffered from pancreatic cancer, was hospitalized. Much of his time was spent at her side, where he heard the anguished screams of the dying and their mourning families and saw the beds of gaunt patients become empty from one day to the next.

“I began to feel more afraid of the pain and screams that they were experiencing than the death itself,” Mr. Park said.

After his mother died, he was adrift and bereft. Discord with his father led him to run away from home when he was 14. By his late 30s, he fell into depression, which he sought to ease by taking pictures. Without meaning to, he found himself drawn to burial plots, ritual sites, and places of prayer — synonymous with marking the end of life or remembering those who died. While sorting through his photos, he was struck by a commonality: the image of mothers praying.