It also houses - with a certain amount of hot-desking - adults, from teachers, health visitors and midwives to speech therapists, social workers and counsellors.
At the core is a nursery school offering full-time places for up to 40 children, who attend from the half-term after their third birthday. There is also a day nursery for younger children and for pre- and post-school care for the nursery pupils - and even a "bear club", providing care for up to 24 children at local primary schools. Parents of one to three-year-olds can attend a "care and toddler club" two or three times a week in the toy library.
Ynyscynon, under the calm and resourceful leadership of Susan Allan, is the pioneering early years centre in Rhondda Cynon Taf. There are two other integrated centres in the authority: the only Welsh-medium centre in the country and a purpose-built centre in a very deprived part of Pontypridd.