Empire Pool and Arena (1934) by Owen Williams.
Building designed for the 1934 Empire Games, incorporating a swimming pool with two flanking terraces of spectator stands. It was designed by Owen Williams who had helped design the neighbouring British Empire Exhibition (including Wembley Stadium) with Maxwell Ayrton in 1924. The building was renamed Wembley Arena in 1978, and is now a world famous concert venue.
Images from Architects Journal and Wembley Park
Cut To The Feeling 