is some debate as to whether the so-called "Great Circle"
was ever a complete circle at all. There are 12 surviving
standing stones around the mound of Newgrange out of a possible
original 35 to 38 orthostats.
"pit" was found to the east of stone GC-2, which
may have been a socket for one of the GC stones in former
times. However, during later excavations a series of 70 pits
were found in a giant arc to the east of the cairn, so it
is not known if a standing stone ever stood at this location.
Great Circle shown in a watercolour painting in 1775
Great Circle (GC) has an average diameter of 103.6m (340 ft),
which is larger than the diameter of Stonehenge, the outer
bank of which is 97.5m (320 ft).
stones of the GC consist of greywacke, which is a type of
sandstone, as well as limestone, granite and other igneous
rocks and stand at a height of approximately 2 metres each.
a number of the existing GC stones are diametrically opposite
each other and many of the opposite pairs are spaced apart
by 103.6 (340 feet) which is exactly 125 megalithic yards
according to Alexander Thom.
Frank Prendergast has produced data which shows that the "Great
Circle" stones were astronomical
and calendrical in function.
revealed that the Great Circle was erected some time after
2000BC, meaning it was the final stage of construction at
is known that the Great Circle was erected when Newgrange
was still in use. It had been put in place before the collapse
of the cairn, which is obvious from the way the cairn slip
material mounted up against the GC stones.
Newgrange was being excavated, one of the GC stones, GC-10,
was found lying prone, and was later re-erected in 1973 when
archaeologists located its original socket.
implement described by Professor Michael J. O'Kelly as an
"iron wedge" was found under the turf near a pit
which may have originally been a socket for stone GC-3. The
archaeologists speculated this implement could have been used
to split the stone - fragments of which may have been found