It was almost square and connected to the Gymnasium by means of a small door. Boxers, wrestlers, and jumpers trained at the 1,680 square-metre court at the centre of the building, which was surrounded by a Doric colonnade of 72 columns and laid with fine sand. Similarly to the Gymnasium, auxiliary closed spaces of various sizes were built around the main training area. All these extra rooms were absolutely necessary, so that athletes could prepare their bodies and minds before their strenuous routines, according to the Greek sporting tradition and ideal; apart from the evident use as changing rooms, it was also where the athletes anointed themselves with olive oil from their aryballos (a special small vase for carrying and pouring oil) and dusted with fine powder a practice which must have originated in ritual, as its purpose remains rather obscure.
After training, this film of oil, powder, and dust from the palaestra would be scrubbed away using a tool known as the stlengis.Benches along the walls provided seating where orators and philosophers would teach the athletes. The doors of the rooms opened to the large court, while most of their façades were decorated with Ionic columns. Today, thanks to relatively recent excavations and restorations, visitors are able to see the lower stone parts of the building, as well as 32 restored columns of the main court out of the original 72.