The planet of Kyrat is an icy planet located in the Orion system. The planet is a test ground for new UNSC ordinance and it was attacked by the covenant during the Invasion of Kyrat.
During the colinization era, Kyrat was found in early 2536. The actual colinization began 3 years later. On 2558, UNSC radar picked up multiple covenant vessels heading torward the planet. The invaders were a group of rouge covenant elites, commanded by the infamous Arbiter, Ripa'Fal. The covenants motive was to eradicate the human population of the planet, then move on only to destroy another planet.
Due to the planets large size and low population, it was widely used to test UNSC ordinance. Such areas were large and uninhibited thus letting large explosive ordinance being used.