Nikolai-Apotheke is worth noticing less as a pharmacy than as one of Flensburg's oldest surviving town houses. The stepped-gable merchant house on Sudermarkt belongs to the late Gothic brick tradition of the Baltic trading towns, and its survival gives the square a visible link to the city's mercantile past.
You do not need long here; this is a look-up-and-linger stop while walking the old town. Its value is in the setting, with St Nikolai, the market square, and the red-brick streetscape around it making the building feel properly anchored.