Answer: The Burning Man Festival
On your average day the search portal for popular search engine Google is a minimalist affair, just the simple primary-colored company logo and the search box. On special occasions, however, Google dresses up their logo to celebrate everything from iconic people (like Frank Lloyd Wright and H.G. Wells) to iconic things (like LEGO bricks and PAC-MAN).
While such custom logos, known as Doodles, are now fairly frequent, in the early days of the search giant they were few and far between. The very first Doodle was intended as a little inside joke between Google founders Larry Page and Sergey Brin, and fans of the Burning Man Festival. In 1998 the two were going to be out of the office to attend the festival and changed the logo to have a Burning Man stick figure behind the second O in Google.
Two years later in 2000, they asked Google intern Dennis Hwang to make a Doodle for Bastille Day. The Doodle proved to be so popular they put Hwang in charge of creating Doodles for other holidays, events, and the birthdays of famous and influential people–over a decade and a thousand Doodles later he’s still at it. You can view the entire collection of past Doodles at the Google Doodle archive.