It was the Brighton Beach End.
See description of the new ground below:
The stadium was literally built in 2001 in a matter of months. It comprises three permanent stands on both sides and at one end, with a temporary stand at the South end of the ground. The three permanent stands are of roughly the same design and height and are quite smart looking, with the Main Stand having a row of executive boxes to its rear. Each is a covered single tiered stand, with good views of the playing action, with perspex wind shields at each side. The stand roofs have perspex panels, helping get more light to the pitch. For a number of seasons the South end of the stadium has been unused but it has now been filled with a temporary structure. This stand is a small uncovered all seated affair. It is just ten rows high and has a capacity of 1360 seats. The corners of the ground are open and they are home to some unusual looking floodlights. The pitch has been rotated 90 degrees from its old position and if you ever visited the old ground, try figuring out where the old Brighton Beach End was located!