The track is cleaned at the iconic Bird’s Nest National stadium in Beijing

A worker cleans the track at the Bird’s Nest National stadium in Beijing on Tuesday, as preparation for the 15th IAAF Athletics World Championship, which will be held on 22-30 August.

The iconic stadium, designed by Herzog & de Meuron, Arup, China Architectural Design & Research Group and artist Ai Weiwei, was built for the 2008 Olympic and Paralympic Games.