Lego has built 12 festive models in the Savoy hotel.
The models are part of its "Rebuild the world" campaign, which champions the importance of creativity as a key 21st-century skill.
The installations are based on a rewrite of The Twelve Days of Christmas, with each line of the song reimagined through the eyes of a child.
Instead of "a partridge in a pear tree", there will be "a dragon-shaped Christmas tree".
The designs will be on display until 3 January and include a tea-drinking lion and a princess’ rocket-castle.
372,931 bricks were used to make the decorations and the process took 2,200 hours to complete.
Visitors can share a photo using the hashtag #BuildToGive and Lego will donate a set of bricks to a child in need.

You can also book into a LEGO building workshop on the weekend of December 1st or 15th, where kids can build and create festive decorations.
Nicola Morgan-Hulme, senior brand relations manager, UK and Ireland, at Lego, said: "As part of our 'Rebuild the world' campaign, this partnership is designed to inspire people of all ages to unleash their creativity and explore the limitlessness of their imagination through play.”
"We hope that the 'Twelve rebuilds of Christmas' will truly inspire people to rebuild the importance of creativity this festive season."