The planet known as Ilum was transformed into a military installation called Starkiller Base by both the Empire and later, the First Order, using terraforming techniques.
Terraforming: This refers to the alteration of a planet's environment. The goal is to establish conditions that support life and prosperity for most sentient species in the galaxy. This involves modifying aspects like the atmosphere and terrain. The Solodoe species had intentions to terraform Plin Minor, but the native Plinovians opposed this, fearing the destruction of their natural environment. Lah'mu is an example of a world that was terraformed. Conversely, Eadu was the site of a terraforming operation overseen by Grand Moff Wilhuff Tarkin. Back in 18 BBY, the Galactic Empire initiated a terraforming endeavor on the planet Ilum.
