Castillo de Grajal de Campos is a Renaissance fortress in León built between 1517 and 1521 by the Vega family, making it Spain's first artillery fortress. Designed by Italian architect Lorenzo de Adonza, the square structure features four distinctive circular towers at its corners and was surrounded by a protective moat. Declared a National Monument in 1931, this exceptionally preserved 16th-century fortress showcases innovative military architecture adapted for early cannon warfare. Though privately owned with limited interior access, its exterior remains one of the most impressive examples of Renaissance military engineering in Castile.
