A large chunk of the Dutch population is clad in orange and heading out early for Queen's Day, the Dutch national holiday, which honors the ruling House of Orange.
There are parties around the country, with the ruling Queen Beatrix due to attend celebrations in the cities of Rhenen and Veenendaal.
With fair skies and an unseasonably warm weather forecast, around a million people are expected to descend on Amsterdam on Monday. The city turns into a giant open marketplace _ lots of beer is consumed and there's live music around the city.
Mayor Eberhard van der Laan has vowed to scale back the numbers pouring into Amsterdam, as past years' celebrations have resulted in hours of gridlock in and around the city.
The massive orange fest is a chance for Amsterdam children to earn pocket change with performances or by selling old toys in parks and along most streets. Young adults prefer the rolling street parties of the city's center as a chance to mingle or dance.
The festivities were disturbed in 2009 due to a failed attack on the royal family _ an unemployed recluse attempted to slam his car into a bus carrying the queen and other members of her family, killing seven bystanders and himself.
This year, there is some speculation in the Dutch media that Queen Beatrix, 74, may set a date for her abdication. Other royalty watchers say the queen intends to remain on the throne for several more years.
Her eldest son, Crown Prince Willem-Alexander, has three young daughters.