Tervakoski

thumb|The Tervakoski Paper Mill in 1900 thumb|The Tervakoski Church Tervakoski (; ) is a small town in Janakkala, Finland. In 2021, there were 3,972 inhabitants.

Puuhamaa () is an amusement park opened in 1984 in the village of Tervakoski, in the municipality of Janakkala, Finland. Like Mikkeli's Visulahti, instead of electrical rides, it mainly offers things to do for children: slides and waterslides, bouncy castles, race tracks, etc. It also has a minigolf course and a video arcade. Its attendance peaks at roughly 5,000 children a day. The park has an entrance fee, but all its features are free.