The castle stands on a volcanic rocky islet that connects to the larger island of Ischia by a causeway (Ponte Aragonese).

[citation needed] Around 1700, about 2000 families lived on the islet, including a Poor Clares convent, an abbey of Basilian monks (of the Greek Orthodox Church), the bishop and the seminar, the prince with a military garrison.

[1] The castle stands on a volcanic rocky islet that connects to the larger island of Ischia by a causeway (Ponte Aragonese).

Along the tunnel there is a small chapel consecrated to John Joseph of the Cross (Italian: San Giovan Giuseppe della Croce), the patron saint of the island.

The first was built in 1737 on the location of a smaller chapel dedicated to Saint Francis, and closed after the suppression of Convents in 1806 as well as the nunnery of the Clarisses.