Harvester

The Harvester is a massive alien spaceship used to destroy planets, and where the Aliens travel in space. It was present and led the Alien attack during the War of 2016.

It appeared as the second most villainous place in Independence Day: Resurgence (2016), with the Queen's Pod as the most villainous place in the film.

Exterior
Each Alien Supreme Commander has a personal Colony mothership that is attached to the Harvester, where the Queen lives. It is far larger than a City destroyer, but the ship designs are similar. The Harvester is heavily protected by plasma cannons, Colony motherships, City destroyers, and a horde of Attackers.

Interior
The interior is vast. The ground acts as some kind of agricultural with an unknown species of crops growing, and whether it's native to the Aliens' home or stolen from another world the Aliens took over is unknown. It is possible, however, that they use these crops to generate oxygen for the Harvester, and maybe to provide food.