Glenfarne and Thur Mountain

Thur Mountain, just over 400m high, in Glenfarne, is only 10km from Cavan Burren and it shares many of the same boulder monument features. This is one of the most exciting areas which may well rival the Burren itself. These discoveries were led by Frank White along with both Gaby Burns and Jim Nolan in 2013. Since 2013 Frank White has discovered over 100 new boulder monuments in the Glenfarne area, 80 of these on Thur Mountain.

Whilst they have all been recorded, and mapped, a more detailed survey needs to be done although several have had a 3D model survey completed by Gaby Burns.

Nearly all the Boulder monuments are glacial erratics with one or two modified boulder features and more than two thirds of them have sculptings. There are also a significant number of propped boulders.


Frank White on 21st September 2014 managed to photograph a unique occurrence of the Equinox sunrise which cast a sunbeam precisely through a split section of a boulder. It appears that sunlight can only properly enter the split and strike the back stone at the equinoxes.

Photo © Frank White
The Equinox sunrise at split rock on Thur Mountain. Large Split stone with “target” stone to rear.


Photo © Frank White
The target stone at rear of split with vertical beam of light striking it – photo taken ten minutes after sunrise.

Photo © Frank White
A very clear Equinox alignment of a dozen or so boulders on Thur – see Google aerial view below.



The Thur exploration came about as a result of the 296º/116º alignments that were found in Burren which are reckoned to be associated with the sunset on the cross-quarters days, St Brigid’s, May day etc. 





View 3D Model

Glenfarne – Thur Mtn LC35