The European Physical Society (EPS), upon nomination by the Belgian Physical Society, has decided to confer a Historic Site Award to the Cyclotron Hall in Louvain-la-Neuve. This place has hosted in 1990 a world-leading nuclear-astrophysics experiment involving for the first time the post-acceleration of a short-lived radioactive element and the successful study of a key nuclear reaction in the stars. This world premiere was the result of an intensive collaboration between research teams from ULB, KU Leuven and UCLouvain. To celebrate this event, a commemorative plate was unveiled on Tuesday 12 October 2021 at the "de Hemptinne" building of UCLouvain, which hosts the Cyclotron Hall.