Upper right corner fragment from Block XII which is in very poor condition. The fragment was found during the 1888-1889 excavations on the Acropolis. Only the head and part of the body of an athlete who participates in the apobates race are preserved. He wears an Attic-type helmet and a cuirass decorated with an inlaid Gorgon head and shoulder straps the top of which is ornamented with lion heads. The remaining part of the block is in the British Museum in London and the Acropolis Museum exhibits its plaster cast.

The frieze on the north side of the Parthenon depicts part of the procession formed by the people of Athens during the Panathenaic festival in honour of the protectress of the city, Athena. The procession's destination was the Temple of Athena Polias on the Acropolis. Its purpose was the transportation of the Panathenaic peplos destined to adorn the age-old xoanon of the goddess and the offer of a grand sacrifice of animals at the Great Altar outside of the temple.

On the north frieze the procession moves along the Panathenaic Way. On its head are youths that lead young cows and rams for the sacrifice followed by more young men who carry water and offerings. Behind them come musicians with flutes and guitars, elders, perhaps officials, holding olive branches, eleven chariots that participate in an equestrian event and finally sixty horsemen divided in ten groups.

The north frieze is fragmentarily preserved due to the explosion of the Parthenon by the Venetians under the command of general Francesco Morosini, in 1687, which damaged mostly the middle part of the long sides of the temple. The drawings attributed to the painter Jacques Carrey, who visited the Acropolis in 1674, just thirteen years before its bombardment by Morosini, are an invaluable resource for our understanding of a few parts of this side of the frieze (Blocks Ι-ΧΙΧ). Three blocks (X, XVIII and XXVI) were removed during the conversion of the Parthenon into a Christian church so that windows would be opened in the blocks' positions. Some of these blocks' fragments were later found on the Acropolis.

The initial length of the north frieze was 58.70 m and consisted of 47 blocks. Today the surviving blocks are divided between the Acropolis Museum and the British Museum in London, where they ended up after they were removed by Thomas Bruce, the lord of Elgin, in 1801-1804 when Greece was still under Ottoman occupation. In order to facilitate their transportation, Elgin's workmen, cut off with saws or crowbars only the faces of the blocks that bore the relief decoration. The Acropolis Museum exhibition includes the plaster casts of the faces of these blocks. On these casts some of the original fragments that fell off the monument, and thus escaped the looting, have been adjusted.