On that sign at the entrance to the bastion:

The plan of Fort Ward consisted of five bastions with positions for 36 guns. The Northwest Bastion illustrates how the entire stonghold appeared in 1864. This bastion is armed with six reproduction weapons based on Fort Ward's original table of armament: Three 4.5" Rodman rifled guns, two 24-pounder smoothbore howitzers, and one six-pounder James rifle.