- from 1878 to 1903: Nicolas Froidebise - Architect.
- from 1904 to 1918: Antoine Ducarmes - Journalist and writer.
- from 1919 to 1944: Rig Desonay called Rigadin - Photographer and draughtsman.
- from 1946 to 1970: Jean d' Espau called Spoo de Spa - Poet and philosopher.
- from 1971 to 1996: Gilles Devecqueterre - Designer and town planner.

    On each Passage Place towards the Obscure World a maintainor is affected. The maintainor fills his functions during a 26 years period and form his substitute during the three last years of his mandate. With regard to the Léopold II Gallery, all the maintaineurs fulfilled their mission completely, except Antoine Ducarmes who was shot for spying in 1918 by the occupant.

    Each maintainor must obligatorily follow a literary or graphic occupation and carry out a "chronicle of the Passage" according to the notes provided by his predecessor. A double of these files of the "memory of the Passages" is preserved on the Obscure Continent.

Poster for an car racing between Brusel and Spa, at a time where
the two worlds had frequent contacts.