Situated upon a moraine that dominates the central part of the Magliasina River, there are the remains of what was called the "Castle of Miglieglia" or of the Magliasina.
The remains are still an enigma. In fact, the lack of in-depth archeological studies, it is not yet possible to establish neither the epoch nor the specific function of this large building, that rose above the river. The dimensions are notable. The outer walls form an irregular square, the sides of which measure 46.40, 40.60, 48.30 and 48 meters in length respectively. The width of the walls varies from 1.05 to 1.20 meters. From the external perimeter of the walls the foundations of the towers are easily distinguishable, forming a square of 9.80 x 7.10 meters.
The only concrete hypothesis ideated until now is that this building was part of a fortified chain that lined the entire valley, from remainers of forts from Ponte Tresa (at St. Martin's) , Pura, Novaggio, Breno, Fescoggia, Mugena and Arosio. This system should have protected a communication road traced by the Romans in the late imperial epoch that, according to tradition, forked off from the Milan-Sesto Calende at Varese, reaching Ponte Tresa, climbing along the Magliasina and descending at Taverne, thus reaching the Monteceneri Pass, and therefore, the Alpine passes as well. The Castle of Miglieglia is a stop along the Path of Marvels (Sentiero delle meraviglie).