If the resort is offering the Hilton Head Island tour, you might enjoy that. You spend a little time at the Coastal Discovery Museum, the ruins of Ft. Mitchell, and some tabby ruins of slave quarters from about 200 years ago. Connie, who does the tour, can probably fill you in on other historic sites in the area, as well.
Beaufort is not far away and has a lot of history, as do Savannah and Charleston.
No matter what time of year we go, though, we have such a hard time making ourselves leave the island or even the resort!