Charleston, South Carolina and Savannah, Georgia are sometimes called "Sister Cities." They are quite different in plan and have their own unique variations on Lowcountry architecture. Charleston was settled in the late 1600s and Savannah in the early-mid 1700s. They share a commitment to historic preservation, art, manners, excellent cuisine and are key destinations for domestic and international tours. Savannah and Charleston are sought out for the wealth of authentic high-style architecture tempered with vernacular materials and methods and the historic events that occurred in both cities. (At least that's what I think...)
They are part of a small group of American cities whose relatively long histories, slower growth during American boom-times when other cities were clearing the deck for modern buildings, and active historic preservation communities make them a treasure trove of historic architecture, urban design, and industrial design (found in old buildings and antique shops.)