Terrain - Free Unity Asset - Packages Collection - 3D Models

Broccoli Tree Creator - Unity Free Download

Broccoli Tree Creator is a Unity Extension for Procedural Vegetation that gives you full control on how your trees and vegetation should behave and look to fit right in your project.

GPU Instancer - Unity Free Download

GPU Instancer is an out of the box solution to display extreme numbers of objects with high performance. With a few mouse clicks, you can instance your prefabs, Unity Terrain details and trees.