The imposing 18th-century 'Land Gate' guards the southeastern (and only land) entry to Cádiz' old town. You can wander the upper fortifications and defence tower, where Spanish- and English-language panels detail visible sights and the evolution of Cádiz' complex fortification system.
Within the Puerta de Tierra's walls are two museums: the Museo del Títere, devoted to puppetry, and the Museo Taller Litográfico.