Erected on a huge rocky outcrop, in a place formerly occupied by an ancient temple dedicated to the goddess Ceres, Castello Ducale di Palena, also known as Castel Forte, according to some accounts seems to date back to the 12th century. Over the centuries it has undergone several modifications, extensions, and destructions due to historical events such as wars and natural events such as the earthquakes of 1706 and 1933.
The fortification is complex and consists of three levels with a roof garden and a panoramic terrace, a central body around which two side wings are developed, and the Clock Tower built around 1956.
The Ducal Castle was also a place of passage for some historically important figures such as ad St. Francis of Assisi and also played a leading role in the various sieges between the great Neapolitan Houses of D'Anjou and D'Aragon.
Today, the top floor of the fort is home to the Geopaleontological Museum, which is rich in fossil specimens that testify to the geological past of the area.