The lighthouse was built in 1830 and stands on grounds scouted by John Smith, close to a confederate Civil War prison camp, Fort Lincoln and Hammond Hospital. Point Lookout Lighthouse is also the oldest integral lighthouse in the country! The grounds are beautiful and chock full of history and nature.
And of course, the lighthouse is rumored to be haunted.
To find the cache, find the most compelling evidence for (and against) haunting. The anachronism will tell the locale.