Immediately adjoining the cathedral to the southwest stands the
Round Tower, built about A.D. 1000. It is 86 ft.(26.21 m) high, has at the base a circumference of 50 ft.(15.3 m) and a diameter of 16 ft.(4.9 m), and is capped with a hexagonal spire of 18 ft.(5.5 m), added in the 14th century. This type of structure is
somewhat common in
Ireland, but the only
Scottish examples are those at
Brechin and
Abernethy in
Perthshire. The quality of the masonry is superior to all but a very few of the
Irish examples. The narrow single doorway, raised some feet above ground level in a manner common in these buildings, is also exceptionally fine. The door-surround is enriched with two bands of pellets, and the monolithic arch has a well-preserved representation of the
Crucifixion. The slightly splayed sides of the doorway (also monolithic) have relief sculptures of ecclesiastics, one of them holding a
crosier, the other a
Tau-shaped staff. Two monuments preserved within the cathedral, the so-called 'Brechin hogback', and a cross-slab, 'St. Mary's Stone' are further rare and important examples of Scottish 11th century stone sculpture. The hogback combines Celtic and Scandinavian motifs, and is the most complex known stone sculpture in the
Ringerike style in Scotland. The inscribed St Mary's Stone has a circular border round the central motif of the
Virgin and Child which echoes that on the Round Tower. == Present ==