Reality has been turned on its head in Cardiff "as if Roald Dahl is at the helm" to celebrate the author's centenary.
Organisers said the laws of physics, logic and the predictable would give way to magic and invention.
Thousands of people gathered at the city's castle after a giant peach made its way through the streets, with some ushered back due to sheer numbers.
Dahl was born in Cardiff 100 years ago this month.
People young and old came dressed up as their favourite Dahl characters as more than 35,000 people made their way to the city for the first day of the event.
Roald Dahl's City of the Unexpected.
Roald Dahl's City of the Unexpected.
“If you trust in yourself, and believe in your dreams, and follow your star. . . you'll still get beaten by people who spent their time working hard and learning things and weren't so lazy.”
Roald Dahl's City Of The Unexpected
Well... isn't that just peachy. (Sorry!)
“In a world whose absurdity appears to be so impenetrable, we simply must reach a greater degree of understanding among us, a greater sincerity.”