Limerick, like many other cities in Ireland, boasts a rich history of remarkable architecture. A document from 1574, prepared for the Spanish ambassador, provides a detailed description of the city's wealth and architectural features:

Limerick is more formidable and aesthetically superior to all other cities in Ireland, with robust walls made of hewn marble. The city is accessible only by stone bridges, one of which features 14 arches, while the other has 8. The majority of the houses are constructed from square blocks of black marble, built in the form of towers and fortresses.

Several notable examples of this architectural heritage remain, including the 800-year-old St. Mary's Cathedral and King John's Castle.

St Mary's Cathedral the older of Limerick's two cathedrals, dates back to the 12th century. The cathedral features a blend of Romanesque and Gothic architectural styles, with Romanesque arches and doorways com plemented by Gothic windows. The plan and elevation of the cathedral reveal that its design has been altered and expanded over time. The original layout of the church followed the form of a Latin cross. Significant additions were made to the cathedral during the episcopate of Stephen Wall, Bishop of Limerick. The Romanesque doorway on the west side is an impressive display of intricate chevrons and decorative patterns. Like many medieval churches in Ireland, the building underwent substantial restoration during the Victorian era. The cathedral holds a dominant position in this medieval area of Limerick City, showcasing a harmonious blend of Romanesque and Gothic architectural influences. The tower of St. Mary's Cathedral was added in the 14th century, and it rises to 120 feet

The main body of St. John's Cathedral was designed by the English architect Philip Charles Hardwick, and constructed between 1856 and 1861. The cathedral features the tallest spire in Ireland, reaching a height of 94 meters, which was a later addition designed by M.A. Hennessy and completed in 1883. The exterior of St. John's Cathedral underwent a complete refurbishment in 2004, including new roofing and repointing of all stonework. Today, the cathedral stands as an imposing structure on an otherwise undeveloped side of the city center. Additionally, an important historical Protestant church, located near the cathedral, is currently in use by Dance Limerick, despite being in need of some repair.

The newest St. Munchin's Church (Church of Ireland) was built in 1827. It stands as a testament to Gothic architectural style, designed by George and James Pain. The church's distinctive four pinnacles atop its tower give it a unique and distinguished appearance.

Located on King's Island, between the Bishop's Palace and the Villiers Alms Houses, St. Munchin's Church has witnessed significant historical transformations. Built in 1827, it underwent renovation in 1980 by the Limerick Civic Trust. The building served as a venue for the Island Theatre Company for a period and is now used as a store for the Limerick Civic Trust.

This freestanding double-height Romanesque limestone church, built in 1851 on the site of a medieval church, features a gabled west elevation with a central Romanesque portal, a blind arcade of three round arches at first-floor level, and a rose window above. A three-stage square-plan tower at the southwest corner supports a splay-foot pyramidal spire with decorative detailing. The church has an apsidal east end and sacristy to the northeast. Its north and south elevations comprise four-bay single-storey aisles with clerestorey oculi, articulated by shallow piers. Roofs are natural slate, with cast-iron rainwater goods and a decorative limestone chimneystack.