Video: St Patrick's Day turns the world green More than 250,000 revelers braved the occasionally snowy, sleety skies to line the streets of Dublin for the traditional holiday parade, a two-mile jaunt through the city's heart involving performers from 46 countries. St Patrick's Day has become a global festival and was marked in skylines across the world as part of a worldwide campaign to floodlight landmarks green at night. This year the pyramids of Giza, the leaning tower of Pisa, Niagara Falls, and the Christ the Redeemer statue overlooking Rio were among dozens of iconic spots that went green for the occasion.