Harvest before it was ravaged by the Covenant
The planet known as Harvest was a Human colony world that, like so many others, was attacked and glassed by the Covenant during the Human-Covenant War. Harvest was notable in that it was actually Humanity's first recorded encounter with the alien empire, since all other Humans who had encountered the Covenant had been killed.
The Battle of Harvest took place here, which was little more than a suprise attack on the Humans that quickly became a rout. However, after the Covenant had glassed the planet, the UNSC were able to eventually reclaim it, and it was there that they began experimenting on speeding up the recovery process of planets that had been glassed.
Harvest was eventually returned to its original state nearly 90 years after it had been glassed, along with Reach, Arcadia and other Human colony worlds.
Harvest after being glassed