In Photos: Dublin on St. Patrick's Day

Thousands of people line the two-mile parade route across the River Liffey to St. Patrick’s Cathedral.

The parade’s Grand Marshal, 19-year-old disability rights campaigner Joanne O’Riordan, greets thousands of cheering fans along the parade route.

More than half a million people from around the world turn out to enjoy the St. Patrick’s Festival Parade.

Young musicians take a few moments before the parade to practice Irish hymns on their bagpipes.

This year's festival theme marks the final installment of a creative trilogy of past, present, and future. This pageant, inspired by the young people in Carndonagh Secondary School in Donegal, reflects on the pervasiveness of digital technology, portraying a world where all the technical tasks, which are currently carried out by phones and computers, are a part of our physical selves. They’re built into our brains, our eyes, our ears, our hands, our mouths.

"March to Dublin" is the official celebratory tune of this year’s parade, and serves as “a declaration of the welcoming spirit” toward visitors to Ireland.

Watching the parade in style.

Sunny skies and record crowds marked this year's celebrations.

Another float in line with this year's theme.

Festival-goers in full flex as they prepare for the day.

Thousands of performers from all over Ireland took to the parade stage on Thursday.

A troupe performs an interpretive song and dance inspired by this year's theme.

Celebrating the day.

A man and his horse wait for the parade to begin.

Young parade-goers watch as the floats go by.

Bands from the U.S., the U.K., Brittany, and Ireland perform, with top honors going to Shorecrest High School Highlander Marching Band from Washington state—which won best overall band in this year's parade.

The parade, which started just after noon on Thursday, saw a sea of green attendees eager to cheer on the live entertainment.

Sharing their Irish pride.

Awash in colorful costumes.

Young children line the walls of this nearby apartment complex at the start of the parade route.

A troupe of laughing hyenas.

Young boys dressed in Ireland’s flag.

Each troupe reflects how young people in Ireland visualize the future of Ireland over the next 100 years.