In the Thurgau Museum of History (free admission), the public is taken through the tumultuous time between the Middle Ages and the modern era. The stone-built defence tower in the heart of Frauenfeld is an imposing feature of the cityscape. For centuries the fortress, which was later extended into a castle, was a focal point of the region's history that encompassed the entire southern Lake Constance region. The reigning Habsburg family lost its dominance over the region, first to the local nobility and the cities, and then to the Swiss confederates. This way, the southern Lake Constance region became a real bone of contention, with Frauenfeld Castle at the core of this chequered history.

The young and the young at heart can experience the upheavals of the era across three floors of the Thurgau Museum of History. The walking tour of Frauenfeld Castle reveals the treasures that the monasteries, churches and castles of the region once housed. For tourists, art lovers and locals, a visit to the court room is one of the highlights of the castle tour. This authentic hall was used as the nerve centre of power, initially by the Habsburg bailiffs and later by the Swiss confederate bailiffs.