Britain's Sophie, Countess of Wessex, stands with storybook characters Winnie the Pooh and Piglet during a children's party at Buckingham Palace in London June 25, 2006. Britain's Queen Elizabeth II was hosting a children's party to celebrate her 80th birthday. [Reuters]

Bob the Builder, J.K. Rowling and 2,000 children took tea with Queen Elizabeth II to celebrate the monarch's 80th birthday.

The grounds of Buckingham Palace were transformed for the day into a series of settings from children's classics, including Winnie the Pooh's Hundred Acre Wood, Mr. McGregor's Garden from "Peter Rabbit," and Thomas the Tank Engine's railway.

Models were dressed as favorite literary characters, including Paddington Bear, Postman Pat and supernanny Mary Poppins.

Britain's Queen Elizabeth II meets author J.K Rowling during a children's party at London's Buckingham Palace, Sunday June 25, 2006. Bob the Builder, J.K. Rowling and 2,000 children were due at Buckingham Palace on Sunday to take tea with Queen Elizabeth II. The palace gardens were being transformed into a fairy-tale playground for the party, held to mark the queen's 80th birthday and celebrate British children's literature. [AP Photo]

"The day's been really special, I've got to see J.K. Rowling and the queen and I've taken loads of photos," said Karlie Williams, 12, from Ebbw Vale, Wales.

Guests were being treated to picnic food prepared by "Naked Chef" Jamie Oliver and a comic show performed by stars including actress Julie Walters and model Sophie Dahl, granddaughter of much-loved children's author Roald Dahl.

"All of the show was brilliant," said Alice Bradford, 12, from Manchester. "I was really surprised when the Queen went on stage at the end. There were so many celebrities."

The children, aged between 4 and 14, won tickets to the party in a lottery.

The queen turned 80 on April 21, although her official birthday, celebrated with the annual Trooping of the Color parade, is marked on June 17.