Fireworks illuminate the world's biggest floating Christmas tree on Dec. 5, in the opening ceremony at Rodrigo de Freitas Lagoon in Rio de Janeiro, Brazil. Christmas lights illuminate the Diagonal Avenue in Barcelona, Spain. Christmas decorations glow in the old town of Vienna, Austria. The city was lit up on Nov. 27, in anticipation of the holidays. A Christmas tree with lights and fireworks are displayed during the holiday season at the Reforma Avenue in Mexico City, on Dec. 5. The artificial Christmas tree measures 367 feet at its highest point. Pedestrians make their way underneath the Christmas lights on Oxford Street shortly after their official switching on on Nov. 3, in London, England. The two main retail streets in London's West End of Oxford Street and Regent Street had a joint switching on ceremony by actors Jim Carrey and Colin Firth. People gather around the Children's Museum which is decorated with Christmas lights in San Jose, Calif., on Dec. 1. More than 50