What was the forerunner of modern coasters?

The forerunner of modern Roller Coasters was the "Russian mountains," which originated in 17th-century Russia. These were large wooden structures that featured hills made of ice or packed snow, where riders would descend on sleds. By the 19th century, these concepts evolved into wooden coasters with tracks, leading to the development of the first commercial roller coaster, the "Mauch Chunk Switchback Railway," in Pennsylvania in 1827. This laid the foundation for the modern roller coaster design we see today.