Dublin sits on the east coast of Ireland at the mouth of the River Liffey, where it empties into Dublin Bay and the Irish Sea. The city's population reached 592,713 in the 2022 census for the city proper, while the Greater Dublin Area recorded 1,450,701 residents, representing approximately 29 percent of the Republic of Ireland's total population. The metropolitan area spans from the Wicklow Mountains to the south through the coastal plain and into County Meath to the north. The Liffey divides the city into a traditional north-south orientation that has historically corresponded with socioeconomic differences, though this division has become less rigid since the 1990s.
The settlement began as a Viking trading port called Dubh Linn, meaning "black pool" in Irish, established around 841 AD near the confluence of the River Liffey and the River Poddle. Archaeological excavations at Wood Quay in the 1970s uncovered extensive Viking-age remains including house foundations, artifacts, and portions of the original settlement walls. The Anglo-Norman invasion of 1169 brought the city under English control, and Dublin Castle was constructed starting in 1204 on the orders of King John. The castle served as the seat of English and later British administration in Ireland until 1922, when it was formally handed over to Michael Collins and the Irish Free State government.
Trinity College Dublin was founded by royal charter in 1592 under Queen Elizabeth I on the site of the dissolved Augustinian Priory of All Hallows. The college's Old Library, completed in 1732, houses the Book of Kells, an illuminated manuscript Gospel book created by Celtic monks around 800 AD. The book contains the four Gospels of the New Testament written in Latin on 340 folios of vellum, decorated with elaborate interlace patterns and figurative illustrations. The manuscript was produced at either Iona Abbey in Scotland or Kells Abbey in County Meath. It was moved to Trinity College in 1661 for safekeeping during the Cromwellian period.
The Georgian architectural character of central Dublin developed primarily between 1714 and 1830, when the city served as the second city of the British Empire and seat of the Irish Parliament until the Act of Union in 1801. Merrion Square, laid out between 1762 and 1764, features terraced houses with brightly painted doors and ornamental fanlights, a style that became characteristic of Dublin architecture. Fitzwilliam Square, completed in 1825, was the last and smallest of Dublin's five Georgian squares. Number 29 on Fitzwilliam Street Lower has been restored as a museum depicting middle-class Georgian life. The Wide Streets Commission, established by an Act of Parliament in 1757, was Europe's first statutory planning authority and redesigned much of central Dublin with wider thoroughfares including O'Connell Street, originally Sackville Street, which at 49 meters is one of Europe's widest streets.
The General Post Office on O'Connell Street became the headquarters of the 1916 Easter Rising when Patrick Pearse read the Proclamation of the Irish Republic from its steps on April 24, 1916. British artillery bombardment during the six-day rebellion left the building's interior gutted, though the 1818 portico survived. The GPO reopened in 1929 after reconstruction. Bullet holes from 1916 remain visible in the columns. The building now houses a museum dedicated to the Rising, opened in 2016 for the centenary.
Kilmainham Gaol, built in 1796, held leaders of every major Irish rebellion from the 1798 Rising through the Irish Civil War. The prison closed in 1924 and fell into ruin before restoration began in the 1960s. Éamon de Valera was the last prisoner held there. The gaol's east wing features a panopticon design where a single guard could observe all cells from a central point. Fourteen leaders of the 1916 Rising were executed by firing squad in the prison's stone breakers' yard between May 3 and May 12, 1916, including James Connolly, who was shot while tied to a chair because wounds from the fighting prevented him from standing.
Dublin Castle's State Apartments occupy the southern range of the Upper Yard, built between 1750 and 1830. St. Patrick's Hall, completed in 1746, measures 25 meters long with ceiling paintings by Vincenzo Valdre installed in 1778 depicting the coronation of King George III, St. Patrick converting the Irish, and King Henry II receiving the submission of Irish chieftains. The hall served as the location for presidential inaugurations from 1938 until 2011, when ceremonies moved to Dublin Castle's courtyard. The castle's Chapel Royal, designed by Francis Johnston and completed in 1814, features gothic revival architecture with carved heads of historical figures including Jonathan Swift and Daniel O'Connell on its exterior corbels.
The National Museum of Ireland–Archaeology on Kildare Street holds the Ardagh Chalice, discovered in 1868 by a boy digging potatoes in County Limerick. The eighth-century chalice stands 17.8 centimeters high, weighing 1,662 grams, constructed from silver with gold filigree decoration. The Tara Brooch, found near Bettystown in County Meath in 1850, dates to approximately 700 AD and demonstrates the technical sophistication of early medieval Irish metalwork with its intricate gold filigree, amber, and glass settings. The museum also displays Faddan More Psalter, discovered in a Tipperary bog in 2006, one of only five early medieval Irish psalm books to survive.
St. Patrick's Cathedral, founded in 1191, is the larger of Dublin's two medieval cathedrals and serves as the national cathedral of the Church of Ireland. Jonathan Swift served as Dean from 1713 to 1745, and his tomb lies in the south aisle alongside that of Stella, Esther Johnson. The cathedral measures 91 meters in length, making it the longest church in Ireland. A door in the cathedral's chapter house preserves a rectangular hole cut in 1492 when the Earl of Kildare offered his hand through the door to the Earl of Ormond to negotiate a truce, originating the phrase "chancing your arm."
Christ Church Cathedral, founded around 1030 by Sitric Silkenbeard, the Norse-Gael King of Dublin, was rebuilt in stone after the Norman invasion beginning in 1172. The crypt, dating from 1172, is the oldest surviving structure in Dublin and extends under the entire cathedral, measuring 63 meters long. The crypt contains the mummified remains of a cat and rat found trapped in an organ pipe in the 1860s, now known as "Tom and Jerry." The cathedral's north wall leans outward by approximately 45 centimeters from vertical due to structural problems that developed in the sixteenth century.
The Guinness Storehouse at St. James's Gate stands on the site where Arthur Guinness signed a 9,000-year lease in 1759 at £45 per year. The current building, constructed as a fermentation plant in 1904, was converted to a visitor center in 2000. It received 1.7 million visitors in 2019, making it Ireland's most visited tourist attraction. The building's design follows the shape of a pint glass, standing seven stories tall. The Gravity Bar at the top provides 360-degree views across Dublin from 46 meters above ground level.
Phoenix Park, established by the Duke of Ormond in 1662, covers 707 hectares within Dublin's city limits, making it one of the largest enclosed urban parks in Europe. The park contains Áras an Uachtaráin, the official residence of Ireland's president since 1938, formerly the Viceregal Lodge built between 1751 and 1754. The park's name derives from the Irish "fionn uisce" meaning "clear water," anglicized to Phoenix. A herd of approximately 400 to 600 fallow deer has roamed the park since the 1660s. The Wellington Monument, completed in 1861, stands 62 meters tall, making it Europe's tallest obelisk.