St. Patrick's Day, celebrated on March 17, honours Ireland's patron saint and national apostle, Saint Patrick—a fifth-century missionary. A national holiday in Ireland, the festivity is marked by a range of cultural events, parades and traditional music and dance enjoyed across the globe. Interestingly, the first St. Patrick's Day parade wasn't held in Ireland but in the United States. The earliest celebration was organised by Irish vicar Ricardo Artur in St. Augustine, Florida, in 1601. Canada's first St. Patrick's Day parade was held in Montreal in 1824. Here, the festival dates to the 17th century, when Irish immigrants brought their traditions to cities like Montreal and Toronto. Today, major cities such as Toronto, Vancouver and St. John's hold large events featuring bagpipes, dancing and Guinness-fuelled festivities. Pubs fill up early, and landmarks glow green to mark the occasion.

On this day, several landmarks in Ireland like the surroundings of Dublin's Samuel Beckett Bridge—seen in today's image—are often illuminated in green, the striking symbol of the festivities. The bridge, which spans over 100 metres across the River Liffey, was named after the Dublin-born writer Samuel Beckett. It was designed to evoke the image of Ireland's national symbol, the harp.