A walkway leading to the beautiful Bethesda Terrace, the Central Park Mall runs through the middle of the Park from 66th to 72nd street. It remains the sole formal feature of Olmsted and Vaux's naturalistic creation. To the north lies the Terrace Bridge, while the Olmsted Flower Bed is located directly south of the Mall.

Once referred to as an "open air hall of reception" by its creators, the Mall was specially designed to accommodate the width of carriages passing through its bounds. Around the turn of the century, these carriages would drop off their wealthy inhabitants at the Mall's starting point, where they could enjoy the natural scenery and mingle with people of lesser status. When these visitors finally reached the Bethesda Terrace, their carriages would be waiting to bring them to their next destination.

Source: http://www.centralpark.com/guide/attractions/mall.html