Enies Lobby is a government-controlled stronghold in the Grand Line. Enies Lobby is located on an island referred to as afternoon island. Enies Lobby leads to Impel Down and the Marine Headquarters directly.
Marineford is the main headquarters of the Marines. It is where Fleet Admiral Sengoku and the three Admirals reside, along with many Vice Admirals and lower officers when they aren't assigned to another base.