  Perpendicularly magnetized nanowires exhibit distinct domain wall types
depending on the geometry. Wide wires contain Bloch walls, narrow wires N\'eel
walls. Here, the transition region is investigated by direct imaging of the
wall structure using high-resolution spin-polarized scanning electron
microscopy. An achiral intermediate wall type is discovered that is unpredicted
by established theoretical models. With the help of micromagnetic simulations,
the formation of this novel wall type is explained.
