The ONYX was built in the Art Deco style of the 1920s with a two-coloured natural stone façade and an impressive foyer. It gracefully combines new architectural elements with older styles that were used in architectural monuments in Westend in the pre-war era. Masterpieces of craftsmanship, such as the natural stone inlays by Frankfurt artist Alexandre Osipov in the 3.30 m high foyer, have been combined with innovative building technology for enhanced noise insulation, security and energy efficiency.

With its height of 55 meters, the building is reminiscent of a New York lifestyle and offers unique, unobstructed views of Frankfurt’s skyline, the Taunus and Spessart mountains and Odenwald forest - with the top floors even enjoying 360 degree panoramic views.