Barnes Lower, county Donegal
C 107 245 - Sheet 2
The larger of two massive standing-stones under a metre apart is over 1.8 metres square, has many cup-marks (some with large rings) and wide, shallow grooves on its E face. The smaller one, shaped like a spearhead, has cupmarks and a cross (a relic of Penal times ?) on its W face. Both faces are lit simultaneously in late morning.
Decorated stones in Britain tend to be important 'marker'stones in astronomical alignments, but I have no information on the alignments of the various stones in Barnes Lower.

In the same townland not far away is a single stone, 1.3 metres high (C108
239),
and farther off, on high ground overlooking Lough Salt (C 122 263), is a three-stone
row whose highest stone is 1.2 metres.
See the Field Guide/Gazetteer for another county Donegal petroglyphic
menhir at Ardmore.