The Forte Spagnolo (Italian for Spanish fortress; locally called il Castello) is a Renaissance castle in L'Aquila, central Italy.

[2] The project was entrusted to a Spanish architect, Pedro Luis Escrivà, an expert of firearms, who had begun to build Castel Sant'Elmo in Naples.

In the following 30 years the heavy taxes necessary to build the fortress impoverished the city, which in 1567 begged the Spaniards to stop the construction; the Royal Court granted the request, and works were interrupted, so parts of the castle were never completed.

The fortress had cost an enormous sum for the times, and Aquila was obliged also to sell the thick silver case containing the body of St. Bernardino of Siena.

The slanted walls would reject enemy fire to the sides; each bastion consisted of two separate and completely self-sufficient environments - called "case matte" - almost independent garrisons on their own.