One billion people live in slums. Their numbers are supposed to double over the next quarter-century. So: Who are those people — and what must their lives be like?

The Norwegian photojournalist Jonas Bendiksen has spent a good deal of time in Indian, Kenyan, Indonesian, and Venezuelan slums, and his website, The Places We Live, features dazzling 360-degree photos of homes and shanties, navigable and altogether immersive, along with audio recordings made by the inhabitants. Prepare yourself to gape, gasp, laugh, cry, and experience every emotion in between: In Mumbai, you’ll meet the Shilpiri family (15 people crammed into a tiny space through which floodwater and garbage regularly stream). In Nairobi, the head of the Dirango household takes great pride in his cramped abode, giving a tour that takes just seconds. “You have to visit somewhere before you judge,” he explains. Thanks, Mr. Bendiksen, for starting us on the journey.