It will be docking at Manila South Harbor.Yes you will need pesos.Transportation is available by the docks.Fort Santiago is around 1.5 miles away , 30 minutes walk. Move towards 25th st., all the way to Bonifacio Dr ( Roxas Blvd) ,cross it....turn left. When you reach the roundabout, stay right along Soriano Ave.You will see the Manila Cathedral on you rightside, then turn left to Gen. Luna to Fort Santiago.