If so, how accessible is the famous captain’s grave? I am a huge history buff and would like to visit this important historical site.

Yes. Sir Francis Drake, famed British naval captain, slaver, politician and pirate is buried in Panama.  However, his grave isn’t exactly accessible.  Actually, divers still look for it as though it were buried treasure.  When Sir Francis Drake was dying of dysentery off the coast of Panama, in 1596, he requested to be suited in full armour and buried at sea.  He was just 55 when he died.  His crew did indeed carry out Drake’s wishes, placing the captain’s body in a lead coffin and dropping it to the bottom of the sea near Portobelo.  Though, his “grave” is not the tourist attraction it would have been if he’d been interred on land, if you’re a true history buff, locals in Portobelo Bay, due south of the Panama Canal on the Caribbean side, are always happy to point you toward where they believe “El Draque” lay.  And, if you’re a diver taking a look around the crystal clear waters of Drake’s Island, then best of luck!