Ancient Monuments

History on the Ground

This site is entirely user-supported. See how you can help.

Ffos Toncenglau cross ridge dyke

A Scheduled Monument in Rhigos (Y Rhigos), Rhondda, Cynon, Taff (Rhondda Cynon Taf)

Approximate Location Map
Large Map »
Street or Overhead View
Contributor Photos »

If Google Street View is available, the image is from the best available vantage point looking, if possible, towards the location of the monument. Where it is not available, the satellite view is shown instead.


Latitude: 51.7109 / 51°42'39"N

Longitude: -3.5653 / 3°33'55"W

OS Eastings: 291945

OS Northings: 202515

OS Grid: SN919025

Mapcode National: GBR HD.3KWK

Mapcode Global: VH5GL.5807

Entry Name: Ffos Toncenglau cross ridge dyke

Scheduled Date:

Source: Cadw

Source ID: 2247

Cadw Legacy ID: GM118

Schedule Class: Defence

Category: Cross Ridge Dyke

Period: Prehistoric

County: Rhondda, Cynon, Taff (Rhondda Cynon Taf)

Community: Rhigos (Y Rhigos)

Traditional County: Glamorgan


The monument comprises the remains of a cross ridge dyke - a linear bank running along the upper edge of the west-facing slopes of a small steep valley situated in moorland at the head of the Rhondda Valley. The tradition of cross ridge dyke building appears to roughly span a millennium, beginning in the middle Bronze Age and lasting throughout the Iron Age (although perhaps with reuse and limited construction in the medieval period). They have been interpreted as territorial boundaries, defnining areas of political influence (including internal territorial boundaries and land allotment within communities) and perhaps having ritual associations. The area covered by the original designation did not relate accurately to the remains on the ground and the scheduled area has been revised in order to rectify the original designation.

The monument is of national importance for its potential to enhance our knowledge of prehistoric land division and perhaps ritual practices. The monument is an important relic of a prehistoric landscape and retains significant archaeological potential, with a strong probability of the presence of environmental and structural evidence. The exceptional size of the cross ridge dyke increases its importance.

The scheduled area comprises the remains described and areas around them within which related evidence may be expected to survive.

Source: Cadw

Other nearby scheduled monuments is an independent online resource and is not associated with any government department. All government data published here is used under licence. Please do not contact for any queries related to any individual ancient or schedued monument, planning permission related to scheduled monuments or the scheduling process itself. is a Good Stuff website.