This is the most notable building in Fuerte del Rey. Its construction was completed in 1796. It has a single floor with whitewashed pointed arches. The choir is set on a raised level facing the altar. The façade is built in ashlar stone, reinforced with strong buttresses. The most interesting feature is the bell gable at the foot of the church. It is arranged in three sections separated by moulding, with a window in the second section framed by ashlar surrounds. The final section, the bell gable proper, is not built in stone, and features two stylised bell openings covered with semicircular arches. It ends in a pediment shaped like a truncated pyramid, decorated at its base with graceful scrollwork.

Dating from the first half of the 20th century, it is one of the oldest flour mills in the province. It was a key facility for the municipality's economy during the post-war years. In 2004, it was listed in the General Catalogue of Andalusian Historical Heritage as a site of ethnological interest.

The small parish church, built on the site of the old Oratory of Santa Catalina and reached by a gentle flight of steps, was inaugurated in 1954. Its narrow, tall whitewashed façade features a simple lintelled doorway framing a semicircular-arched entrance with a broken pediment holding a cross, topped by a bell gable with three bell openings arranged in the shape of a truncated pyramid.

Located in the Barriada Santa Ana, it was built in 1968. It houses images of San Miguel, San José and the Immaculate Conception.

The castle played an important role at one of the key strategic points controlling the Guadalquivir and Guadalimar rivers. Its origins probably date back to the Caliphate period, although it was destroyed by Ferdinand III in the first third of the 13th century. Once under Christian rule, the castle was rebuilt between the end of that century and the beginning of the next. Its most authentic feature is its magnificent keep, square in plan, which houses two superimposed rooms inside, covered by barrel vaults. It was declared a Site of Cultural Interest in 1985.

The Hacienda del Pilar, which takes its name from the image of the Virgin under this title placed on its façade, was built from 1904 onwards as a working farm estate and later remodelled into a private noble residence for receiving dignitaries. Owned by José del Prado y Palacio, former Minister of Public Instruction and Marquis of Rincón de San Ildefonso, it hosted Alfonso XIII during his visit to Jaén in 1916. It was approached through carefully tended English-style gardens with a monumental fountain at their centre and another, in Seville style, to one side. The façade, with two columned galleries — one of them glazed — featured wooden columns and finely worked ironwork, all in a markedly eclectic style. Inside, this eclecticism continued with an element of special interest: a Renaissance courtyard belonging to a palace in Andújar, demolished in the second decade of the century and acquired and transferred to El Pilar by its owner. Nine slender columns, eight arches with cushioned coffering, spandrels, medallions and noble coats of arms were removed from their original building and brought here, along with a fountain with a wide basin, four shells and two bowls, decorated with caryatids. The building also had spacious rooms, a small theatre and a hall with fine furnishings.