Incredible photographs show thousands of people competing to build the tallest human tower in a traditional contest in Spain.
The Concurs de Castells is a biennial event held in Tarragona, north-east Spain, that sees teams of up to 500 people form impressive towers, known as castells, that are up to 10 tiers high.
The tradition dates back to the 18th century in the Catalonia region and is believed to originate from the human towers built by dance groups.
Competitors in the same team wear the same colour at the contest. Each team, which includes children, carefully builds its towers with their strongest and heaviest members interlocking their arms at the bottom. Meanwhile, the lightest make a dangerous ascent to the top.
The teams compete over five rounds, with points awarded depending on the difficulty and height of each castell.
However, the competition is not without danger, with some suffering injuries when the towers topple over.
Around 20,000 spectators from around the world come to watch the spectacle, which is listed on Unesco's cultural heritage list.