The Latvian city of Riga has attempted to break the Guinness World record for the world's largest Rube Goldberg machine.
A Rube Goldberg machine is an apparatus that is deliberately made to do a task in the most complicated way, often involving a long, convoluted series of actions.
This machine used 400 various parts and links to set in motion - a chain reaction that culminated in switching on the lights on the Christmas tree.
"On December 2 [we] planned to beat the record [currently held by Hungary, with 383 steps] with a 400-step long machine, which will culminate in the Town Hall Square spruce lighting up," Riga city council promised.
The machine used an eclectic range of devices, including balls, wheels, levers, a fan and a coffee maker.
Hundreds of people turned up to watch. It took 10 minutes for the machine to finish its work, and the crowds cheered when the lights were successfully lit.