Kilmainham Gaol is one of the largest unoccupied gaols in Europe. It opened in 1796 as the new county gaol for Dublin and finally shut its doors as such in 1924. Today, the building symbolises the tradition of militant and constitutional nationalism, from the rebellion of 1798 to the Irish Civil War of 1922-23. The great collection consists of a wide variety of object types, including manuscripts, photographs, newspapers, weaponry, artwork, medals, uniforms and personal effects especially related to the political imprisonment in the 1916-23 period, as well as the experience of women during the Civil War.

It was built on a site of a Jesus college. It was a foundation, set up by clerics from Madrid's Royal Monastery (Monasterio de la Visitación), under the patronage of the princes Carlos María Isidro de Borbón and his wife, María de Asís de Braganza y Borbón. The monastery was built in neoclassical style, between 1826 and 1832. On the outside, the facade is made from black and red marble, featuring the shields of Spain and Portugal, Saint Charles Borromeo, Saint Jane of Chantal and Saint Francis of Assisi. Inside the church, built in the shape of a Latin cross, there is an interesting collection of religious paintings by the Court painter, Vicente López and his school (Valencia)

On the north side of Dublin Bay lies the mythic Howth peninsula. An exclusive neighbourhood, the island is home to a yachting harbour, artisan restaurants, and a quality farmer's market. Howth's natural beauty makes it a true gem for a wanderer looking to escape the city. The dramatic cliffs and hill walks welcome explorers. For an interesting hike, make sure to follow the "Bog of Frogs" loop! Howth Summit Viewpoint and a stroll on Claremont Beach offer breathtaking views, while Howth Castle, St Mary's Abbey, and "Ye Olde Hurdy Gurdy Radio Museum" provide a sense of the peninsula's heritage. As well as this, visitors can take the ferry to Ireland's Eye Bird Sanctuary in summer.

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.