It was at the Rijksmuseum, Leiden, in 1997 that Gaba inaugurated his major work, the Museum of Contemporary African Art, a project in which the artist installed 12 'rooms' of a nomadic museum in various institutions over a period of five years, culminating with his presentation of a 'Humanist Space' at Documenta 11. Other 'rooms' include the Museum Restaurant (shown at W139, Amsterdam, in 1999), the Games Room (shown in Besançon, France, in 1999 and in Brussels and Gent in 2000), the Library of the Museum (Witte de With, 2001, and published in 2001), and the Salon (Palais de Tokyo, Paris, 2002).
The Museum of Contemporary African Art (1997-2002) was acquired by Tate and exhibited at Tate Modern, London, in 2013. The Library of the Museum was donated by Gaba to the city of Cotonou as part of his project Musée de l'Art de la Vie Active (MAVA). Gaba's survey exhibition Museum for Contemporary African Art & More showed at the Museum de Paviljoens in Almere, the Netherlands; the Kunsthalle Fridericianum in Kassel, Germany; and the Centro Atlántico de Arte Moderno in Las Palmas, Canary Islands, in 2009/10.