Four hundred million years ago, the rivers of north and mid-Wales drained towards
the south-east leaving deposits of sandstone and limestone, later to be followed
by the entire area being flooded by the rising sea level at the thawing of the Ice
Age. Two million years later the early River Wye began to flow over these deposits,
cuttings its way through the rocks it gradually eroded as the sea level fell, to
form today's large sweeping loops. The course of the Wye developed slowly, creating
a sloping sandstone valley with steep limestone outcrops and spectacular cliffs giving
superb vantage points.
The origins of the River Wye are deep within the hills of Wales at Plynlimon, a heather-clad
mountain dominating central Wales. From its birthplace, it gently meanders some 248km
(154 miles) through five British counties in both England and Wales.
The journey starts as a slow, trickling stream in the Welsh hillside, crossing the
border into England at Hay-on-Wye to flow through the Herefordshire plains, then
crossing the border returning to Wales at Monmouth to head southwards to re-join
its sister river, the River Severn, in the Severn Estuary at Chepstow. Throughout
its length, it winds and curves its way through undulating rural countryside, through
an Area of Outstanding Natural Beauty and Site of Special Scientific Interest.
Some of the best areas of ancient British woodland are to be found here with dense,
broadleaf woodlands providing a varied range of habitats for birds, insects, flora
and fauna and wildlife alike. The trees and overhanging branches provide a tranquil
and sheltered canopy over a safe haven for the many rare plants nestling in the dense,
rich undergrowth.
