At the north end of the garden, workers built a flat base for the mausoleum. It had to be strong. The domed mausoleum and two other buildings would sit on it. The site was close to the river, and the ground was covered in sand and loose soil. Workers had to dig down until they hit hard ground on which they could build. When the platform was done, builders began the mausoleum. As the most important building in the complex, it is made of the most expensive materials. Workers first built the walls with bricks and mortar. Mortar, when it hardens, holds bricks together. Once the walls were complete, they were faced with, or covered in, sheets of white marble.
The heavy white marble was held in place with iron pins and clamps. Workers then built the tomb’s domes. They built a large central dome surrounded by four smaller domes. Like the walls, the domes were built of bricks faced with white marble. The workers built identical buildings on either side of the tomb. To the west is the Taj mosque, a Muslim place of worship. To the east is the matching mihman khana. This hall was used for important visitors and for celebrations in memory of Mumtaz Mahal. At each corner of the tomb platform is a minaret. This tall, thin tower is used in Muslim sacred rites.