Baglan Energy Park is one of the best brownfield sites in Wales, particularly in terms of the notable vascular plants, bryophytes and invertebrates that have been recorded there. It is, in fact, a biodiversity hot-spot and one of the most species-rich areas in Glamorgan. At the moment we know much less about the macro-fungi there, but recent, preliminary surveys indicate that there is a good diversity of species, many of which (not surprisingly) are typical coastal (sand dune) species such as Clitocybe barbularum, C. rivulosa, Melanoleuca cinereifolia, and Inocybe agardhii. A few more are shown in photos below:
Llansamlet Enterprise Park has lots of wooded groves and drive-by observation indicates that some of them have lots of fungi fruiting in them. One that I stopped (very briefly) to look at near the Go Outdoors outlet had some nice groups of Matt Knight (Tricholoma imbricatum) and Bloody Brittlegill (Russula sanguinaria) associated with pine, and large amount of Clustered Toughshank (Gymnopus confluens).
I suspect that there is a large, unrecorded diversity of fungi here.