The stone stele (with inscriptions in Polish) features a bronze medallion in deep relief, depicting the face of the dying Adam Mickiewicz (1798-1855). It is undoubtedly one of the masterpieces of late-Romantic French sculpture.

The author, Auguste Préault, considered the Mickiewicz medallion to be 'the best thing he had done'. He attached great importance to exhibiting a replica at the Paris Salon in 1868. In reviews of that exhibition, the work was highly praised (by Odilon Redon and Emile Zola, among others). Among Préault's many tombstones, it stands out for its unusually bold (against the background of all sepulchral art of the century, anyway) depiction of agony. Contrary to popular belief, however, the medallion is not a representation of the poet's death mask.

The circumstances of the medallion's commission are unknown. The sculptor may have known Mickiewicz personally through his contacts with the French historian Jules Michelet. He became friends with the poet's son, Władysław, but probably while working on the medallion for Montmorency, as evidenced by Władysław Mickiewicz's funeral speech at the sculptor's funeral. Préault's drawing of the medallion, now known only from an engraving by Firmin Gillot in 1867, gives the impression of having been made 'ex-post', rather than as a preparatory sketch; it may also have been for presentation to the commissioners. The work was placed in Montmorency as early as the end of 1866, but the ceremonial inauguration of the monument - with a famous speech by Victor Hugo - did not take place until 21 May 1867. From then on, Préault's medallion was repeatedly reproduced and depicted in various graphic travesties (e.g. by M.E. Andriolli, B. Zaleski, A. Regulski).

A plaster model of the sculpture is in the Bibliothèque Polonaise in Paris. Préault was also probably the author of the lost bronze medallion of Celina Mickiewicz (formerly there). Mickiewicz's ashes were exhumed in 1890 and moved to the crypt in Wawel Cathedral.

In 2020, the sculpture on the nagorbek was cleaned and secured.