Meanwhile, the Eisteddfod's organisers are planning to turn swathes of Cardiff Bay into an "experimental maes", by closing roads to set up the stalls, exhibits and attractions usually found on the festival field.
Sian Eirian, Eisteddfod director, said: "We want an environment where our children can roam around freely.
"We're aiming to create an artistic village with the best of contemporary Welsh-medium youth culture for a local Cardiff audience, and for visitors who might not have experienced the Eisteddfod."
Around 40,000 youngsters from across Wales are expected to compete for a chance to perform at the Wales Millennium Centre at the end of May. Past Urdd winners include film star Ioan Gruffudd and opera singer Bryn Terfel.