Around the late 11th century in the Heian period, dry rocky landscapes were built as a part of mainstream gardens. The professional landscapers back then were called "ishitate-so", meaning "monks who arrange rocks." It might sound a bit strange to us, modern citizens, but since Buddhism was so critical in the art of gardens in those days, it wasn't surprising at all that monks were the ones responsible for designing and creating Zen gardens. It wasn't until the Muromachi period that the Zen rock garden was fully developed, rose to its fame and continued its legacy to this day. Muso Soseki, a great Zen monk, was said to be the father of Zen landscaping who created some of the oldest rock gardens and brought popularity to this enigmatic landscaping technique.
