The major sea defense for Manila Bay, during the first half of the 20th century. The Japanese took Corregidor after heavy fighting on the Bataan Peninsula
The WW2 artifacts and ruins are a testament to the fury of the attacks and the defense, and should be on everyone's must see attractions in the Philippines.
Sun Cruises out of Manila run day trips, and overnight packages.
Bangkas can also be hired from Marivelles, at the tip of Bataan.
Margarita Station has some nice shots from a flight by the A.B.C. Hotel's helicopter on their website on this link.