You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Charleston,_South_Carolina

Context:
Charleston is the oldest and second-largest city in the U.S. state of South Carolina, the county seat of Charleston County, and the principal city in the Charleston–North Charleston–Summerville Metropolitan Statistical Area. The city lies just south of the geographical midpoint of South Carolina's coastline and is located on Charleston Harbor, an inlet of the Atlantic Ocean formed by the confluence of the Ashley and Cooper Rivers, or, as is locally expressed, "where the Cooper and Ashley Rivers come together to form the Atlantic Ocean."

Question:
Charleston Harbor is formed on what ocean?

Atlantic Ocean