The base lies between the two largest windward O'ahu communities of Kailua and Kāne'ohe, and the main gate is reached at the eastern end of Interstate H-3. The main access to the base is by either H-3 or Mokapu Road. MCB Hawaii is located on the windward side of Oahu, approximately northeast of Honolulu. Marine Corps Base Hawaii occupies the entire Mokapu Peninsula, of . Two areas of the base are classified conservation land which includes the Ulupa'U Crater area (northeast peninsula) and the Nu'upia Pond area (at the Mokapu Road).