The Wall Museum is located in the basement of the "Casa del Paso" building, on the Salesas Campus of the Miguel Hernández University. It also houses an interesting and well organised archaeological site, set up after various stages of excavation between 1998 and 2000. Significant architectural heritage sites are well conserved: The town wall, four watchtowers dating back to the Almohad era (Designated Cultural sites since 14/12/1998), Arab baths, Islamic and early medieval streets and homes, a Gothic palace and architectural remains of the Casa del Paso (17th Century). Furthermore, remains dating back from the second half of the 12th Century to the 20th Century have been recovered. During the visit, around the perimeter path and glazed walkways, there is also a variety of complementary resources to help interpret the findings, such as display panels, scale models, signposts, display cases and a video.

Built on the land occupied earlier by the Corpus Christi hospital, one of the city's medieval hospitals. In 1558 the city exchanged plots with Archishop Esteban Almeyda and the hospital was relocated to the Parish of Santiago. The building may have started in the 16th Century, soon after the establishment of the Orihuela Bishopric. It underwent profound changes in the 18th Century under the reigns of Bishops José Flores Ososrio and Pedro Albornoa Tapia. In the mid-20th century, it lost its original functions, was restored at the beginning of the 21st Century and is currently home to the Diocese Museum of Sacred Art. At the back, facing the river, there is a gallery with semi-circular arches. Inside, another striking feature is the cloister with heraldic decoration, the main staircase of Alicante marble and the dome built on an octagonal base, with exterior cobalt blue glazed tiles.

First built in the 17th century following the seizing of Lille by French forces, the Citadel is an impressive star-shaped fortress which now houses the French Rapid Reaction Corps. Guided tours of the Citadel are held monthly. The park area surrounding the fortress contains pleasant greenery and the Lille Zoo.