The earliest flat plan of a three-dimensional flower bed

Quick answer：

The earliest flat plan of a three-dimensional flower bed refers to the initial design or blueprint of a flower bed that incorporates立体 elements, such as raised platforms or stepped structures, to create a visually appealing and functional garden feature. This concept dates back to ancient civilizations, where such plans were used to enhance the aesthetic value of gardens. Detailed plans from various historical periods can provide insights into the evolution of garden design and landscaping techniques.