Facing Trinity College across College Green, this sweeping Palladian pile was built to house the Irish parliament and was the first purpose-built Parliament House in the world. The original building, the central colonnaded section that distinguishes the present-day structure, was designed by Sir Edward Lovett Pearce in the first half of the 18th century.

When the parliament voted itself out of existence through the 1801 Act of Union, the building was sold under the condition that the interior would be altered to prevent it ever again being used as a debating chamber. It was a spiteful strike at Irish parliamentary aspirations, but while the central House of Commons was remodelled and offers little hint of its former role, the smaller House of Lords (admission free) chamber survived and is much more interesting. It has Irish oak woodwork, a mahogany longcase parliament clock and a late-18th-century Dublin crystal chandelier. The tapestries date from the 1730s and depict the Siege of Derry (1689) and the Battle of the Boyne (1690), the two Protestant victories over Catholic Ireland. In the niches are busts of George III, George IV, Lord Nelson and the Duke of Wellington. There are tours of the House of Lords (10.30am, 11.30am and 1.45pm Tuesday), by Dublin historian and author Éamon MacThomás, which include a talk as much about Ireland and life in general as the building itself.

Also part of the complex, and reached via the sedate Foster Place, is the Bank of Ireland Arts Centre, which hosts a variety of cultural events, including classical concerts and regular free lunchtime recitals and poetry readings. It also screens an eight-minute film about banking and Irish history, called the Story of Banking ([tel]671 2261; adult/concession €2/1.50; screenings hourly 10am-3pm Tue-Fri). An exhibition features a 10kg silver-gilt mace that was made for the House of Commons – it was retained by the Speaker of the House when the parliament was dissolved, and in later years it was sold by the Speaker's descendants and was bought back from Christies in London by the Bank of Ireland in 1937.