Iolo Williams explores Singleton Park in Swansea in the first of a new four-part series of Iolo's Great Welsh Parks. Iolo discovers the wilder side of this urban park when he tries to track down foxes and an elusive parakeet, carries out an experiment on a pair of nest-building long-tailed tits, investigates what the local peregrine has been eating and finds out about the many different types of insects living in the colourful botanical gardens.