The site is an important and extensive example
of unimproved species‑rich grassland. There is a thriving colony of
the marsh fritillary butterfly in these pastures. Isolated bushes
of alder buckthorn in the hedgerows support the brimstone
butterfly, which is a very local butterfly in Wales.
Managing this site
The site is under private ownership. The special features of
this SSSI and CCW’s views about site management have been
summarised in a Site Management Statement, addressed to the owners
and managers of the land. The statement can be found in the
resource section below.
There is no public access to this site.
Caeau is the plural of cae (field). Afon means ‘river’ (afon)
and Gwili may connect with gwyl ‘kind, generous, unobtrusive’; it
is followed by the river name suffix –i.