Watch: Here's how the biggest cities of the world welcomed 2015

In one of the first major celebrations of the new year, the Australian city of Sydney put up a massive fireworks display that was watched by millions of people. Earlier, New Zealand also rang in the new year with a huge fireworks display launched from Auckland's landmark Sky Tower structure. Other like Pyongyang, Hong Kong, Dubai and Moscow gradually began hailing the advent of a new year in 2015. In London, the spectators were treated to a fireworks display near the London Eye. One of the last midnight celebrations were held on Copacabana beach in Rio de Janeiro, where more than 2 million people watched a huge fireworks show. Braving cold temperatures and crowded conditions, about one million people crammed into the Crossroads of the World to participate in the annual party. They watched the giant glittering ball in New York City drop in Times Square, to mark the beginning of 2015.