There are, as you’d expect, numerous war monuments and ruins on the island. Significant sights include General MacArthur’s HQ, the mile-long barracks, various gun batteries and the Spanish lighthouse, which offers good views over Manila Bay. Also worthwhile is the Japanese Cemetery, which is understated and formal.
Admission to all of the above is included in the packages run by Sun Cruises, Corregidor’s main tour operator. Tours are conducted on open-sided buses modelled on the electric trolleys used by the Americans. Otherwise there are walking tours (P1800 not including lunch), though you won't cover as much ground.
If you opt to take the ferry but not join the Sun Cruises tour, you can sign up for a more engaging, personalised tour with Old Manila Walks.
Staying on the island offers a peaceful perspective after the day-trippers depart. The main place to stay is the Corregidor Inn, operated by Sun Cruises. There's also a separate dormitory for groups only.
The only restaurant on the island is at Corregidor Inn, where a buffet lunch is served as part of the package tour, or you can order à la carte.