The main entrance to the enclosure is the Lion Gate, which is located on the complex's outer wall. There was a painting of a lion between the lintel of this gate and under a machicolation, the origin of which is unknown, but it appears in Richard Ford's drawings from 1832. In 1876, Joaqun Domnguez Bécquer restored this painting. In 1892, a tile mural designed by Manuel Tortosa y Fernández with historical advice from José Gestoso replaced the painting. The tile was created in the Mensaque factory and depicts a Gothic-style lion holding a crucifix in its right claw and a flag in its left claw. A phylactery on the chest reads in Latin Ad utrumque, which means 'for one thing and for another,' with the word 'paratus' missing; Ad utrumque paratus, which means 'prepared for one thing and for another.'

The name Lion's Gate is most likely from the nineteenth century. This gate was previously known as the Montera gate. According to Ortiz de Ziga (17th century), it was named this because it was where the king would go hunting with his hunters. This hypothesis is supported by the fact that Pedro I's father, Alfonso XI, was such a hunter that he wrote a hunting book. The name came from the fact that it was decorated with hunting reliefs, according to José Gestoso. The reliefs of two worn poly-lobed medallions can be found on the arch's left side. One of them has the appearance of a four-footed animal.

The courtyard of the Lion is beyond the doorway. At the back of the courtyard is an Almohad wall with three porticoes that appears to have been reinforced later. The arches were originally horseshoe arches, but during the Christian period, they were converted to round arches. The courtyard of La Montera is located behind this wall.