KASTOR LOUNGE
A new beginning for European wall sculptures made of natural stone

The Kastor high-rise building in Frankfurt am Main got a new foyer in 2025. Visitors now enter a space that has been redefined in many details. Cream Royal limestone characterises the walls throughout. The highlight here, however, is the parametrically designed natural stone sculpture covering the entire wall area behind the counter.

What at first glance looks like mere rippling reveals itself on closer inspection to be a paradoxical, extremely sophisticated sculptural design. Although the idea is directly linked to the 3,000-year-old tradition of ancient Egyptian columns and classical Greek temple construction, its complexity meant that it could only be realised today, in the 21st century.

It is likely to be the largest wall sculpture made of natural stone to have been designed and produced in Europe in the last 50 years.

The wall sculpture combines the two contrasting fluting styles of ancient columns, which were originally developed by the Phoenicians and the Greeks. Starting concave at the bottom, the elements curve outwards more and more towards the top until they become their opposite, a convex shape.

Widely swinging arcs of light are ‘engraved’ into the strictly vertical orientation of the elements. The LED light strips provide additional illumination for the room and also run concave on one side, while on the other side they trace the convex shape of the columns.

And this is the spectacular technical feature: the arcs mark the exact point for each individual flute where the zero point between its convex and concave design lies. They meet flat at the arc in different bends. This means that each individual flute follows a precisely planned, individual course.

The smooth transitions posed an enormous challenge in terms of the precision required for planning and manufacturing the elements. No two elements are alike, which meant that the sculpture could not simply be tiled with serial elements, even though this might appear to be the case at first glance.

Rather, it is precisely for this reason that one can speak of a large wall sculpture, because the object was created over its entire height and width by precisely sketching the individual flutes and milling them out of natural stone with equal precision.

The fluting of the wall sculpture looks similar everywhere and yet is different everywhere. In this sculpture, we encounter a technically new aesthetic expression of modern architecture.

To this day, modern façades still predominantly appear in the style of classical modernism. Their essential features are haptically neutralised flatness, grid patterns and serial arrangement.

The wall sculpture by TEK TO NIK Architects for the new KASTOR foyer proves that modernism now has the technical capabilities to build on the era of an individual and, above all, sculpturally formed façade language.