Four miles southeast of Portland on Cape Elizabeth, 90-acre Fort Williams Park is worth visiting simply for the panoramas and picnic possibilities. Stroll around the ruins of the fort, a late-19th-century artillery base, checking out the WWII bunkers and gun emplacements that still dot the rolling lawns (a German U-boat was spotted in Casco Bay in 1942). The fort actively guarded the entrance to Casco Bay until 1964. A favorite feature of the park is the Portland Head Light.