The Hunting Grounds (also known as Hunting Range in the SNES/PS version) are a location in Chrono Trigger that appears during Prehistory. Here, characters can hunt creatures that reward Petals, Fangs, Horns, and Feathers. It is also one of the only places where a Nu can be fought.
In the year 65,000,000 BC towards Dactyl Nest, you can see a niche in the woods to the right. This is it.