The Prince of Wales and The Duchess of Cornwall have visited the BBC's New Broadcasting House on Tuesday, as part of a day celebrating British radio.
They met staff from Radios 1, 2, 3, 4 and the World Service on a tour of the BBC's London headquarters.
They went on to visit commercial stations at Global Radio, including Classic Fm, Heart and Capital, and Bauer Radio, home to Kiss FM.
New Broadcasting House was officially opened by The Queen in June last year.
It provided one of 2013's most memorable TV moments, as she appeared behind the newsreaders live on the BBC News channel.
Prince Charles and Camilla were welcomed by some of the BBC's biggest radio presenters, including Radio 2's Chris Evans and Jo Whiley, Gemma Cairney from Radio 1, and Radio 4's Kirsty Young and Mishal Husain, as well as the controllers of the biggest national stations.
They then took a tour of Europe's largest live newsroom at New Broadcasting House, speaking with radio news staff about their roles, programme running orders and the technology they are using.
Radio 4 newsreader Kathy Clugston also talked them through her upcoming 11:00 GMT news bulletin, in which the final item was a story about their visit.
The newsroom serves 10 national and 40 local radio stations, while the World Service is transmitted around the world in English and 27 other languages.
During a visit to the Radio 1 studios, Prince Charles and Camilla joined DJ Fearne Cotton in the Live Lounge to watch a performance by singer Tom Odell.
They went on to the headquarters of Bauer Radio, a patron of The Prince's Trust, where they met Kiss FM's Sony Award-winning breakfast show team Rickie, Melvin and Charlie.
The couple also heard from staff working on Celebrate Success, a Princes Trust initiative rewarding young people who overcome barriers and develop new skills..
Their tour culminated at Global Radio's headquarters in Leicester Square, where Prince Charles and Camilla met presenters including Jamie Theakston, Emma Bunton, Myleene Klass, Aled Jones, Dave Berry and Lisa Snowdon.
Global is the UK's biggest commercial radio company, owning the three biggest commercial networks - Capital, Heart and Classic FM - as well as Smooth, LBC, and Gold.