The Hanging Gardens of Babylon—one of the Seven Wonders of the World—is the first recorded rooftop garden.
There are more than 1 million roof tiles covering approximately 4 acres, sitting over the structure. They were made in Sweden.
A roof is the top surface of the building. The plural of 'roof' is 'rooves' or 'roofs'. The roof keeps out rain and snow and protects people from the sun. Some rooves are sloped, or pitched, so the rain and snow fall off easily. Some rooves are flat, but even flat roofs have a little bit of pitch so the water can flow away towards a drain.