Neath children's unit is home to 'most complex' youngsters
Calls for youth justice to be a devolved matter have been echoed by the children's commissioner for Wales.
Keith Towler said it needed to be done soon and would help cut crime.
The Youth Justice Board currently has responsibility in both Wales and England.
In March, a report, external on Welsh powers recommended youth justice be managed in Wales which Mr Towler said would make a "massive difference" in the way young people in trouble are supported.
Nicola Smith was given exclusive access to Hillside Secure Children's Home in Neath, which has beds for 10 young people