Mardi Gras (French for "Fat Tuesday") is the day before Ash Wednesday, and is also called "Shrove Tuesday" or "Pancake Day". Mardi Gras is the final day of Carnival, though the term is often used incorrectly to describe the days and weeks preceding Fat Tuesday. Carnival begins 12 days after Christmas, or Twelfth Night, on January 6 and ends on Mardi Gras, which always falls exactly 46 days before Easter. Perhaps the cities most famous for their Mardi Gras celebrations include Venice, Italy; Mobile, Alabama; New Orleans, Louisiana; and Rio de Janeiro, Brazil. Many other places have important Mardi Gras celebrations as well. Carnival is an important celebration in most of Europe, and in many parts of Latin America and the Caribbean.
Carnival is celebrated in several Argentine cities in the subtropical northeast. Carnival in Buenos Aires is notable for the dancing murga troupes.
The large LGBT pride festival in Sydney, Australia is called the Sydney Gay and Lesb
Source: http://en.wikipedia.org/wiki/Mardi Gras