MQ Libelle, Rooftop structure at Leopold Museum, Vienna, Austria.

MQ Libelle is a rooftop structure on the Leopold Museum that extends over several hundred square meters and features glass walls creating a floating appearance. The structure includes an open terrace and a kiosk serving refreshments.

The idea came in 2007, when Leopold Museum commercial director Peter Weinhäupl proposed a rooftop addition and Laurids Ortner drafted a study. Plans were presented publicly on 7 April 2014; the original two-storey design with indoor restaurant was cut to one storey with a terrace kiosk. Ground was broken in August 2018 after the museum roof was renovated, and the structure opened in 2020, the MuseumsQuartier's first spatial expansion since 2001.

The name Libelle (dragonfly) was chosen by the Ortner architects for the airy, light, hovering look of the rooftop pavilion. Eva Schlegel's outer skin, veiled, consists of 60 glass panes marked with about 2.35 million points, plus 250 solid glass cones along the vertical joints. Brigitte Kowanz contributed three steel light rings, 13.5, 10.5 and 8.4 metres across, whose layout mirrors the building's floor plan; two overhang the roof edge.

Reach the roof via two exterior lifts on the outside of the Leopold Museum; entry is free, with fixed opening hours and a winter break. The terrace has a gastro kiosk with a garden, run by the operators of Café Leopold. Two of the three light rings overhang the roof edge.

The architects chose the name Libelle for the roof position and the airy, light, floating look of the steel-and-glass pavilion. Eva Schlegel's outer skin, veiled, consists of 60 glass panes marked with about 2.35 million points, plus 250 solid glass cones at the vertical joints.