POMONA or MAINLAND, central and largest island of the Orkneys, Scotland. Pop. (1921), 14,083. It is 25 m. long from N.W. to S.E. and 15 m. broad from E. to W. ; area, 190 sq.m. ; but where the coast is cut into, on the N. by Kirkwall Bay and on the S. by Scapa Flow, the land is less than 2 m. across.
The west coast is almost unbroken, the bays of Birsay and Skaill being the only bays of any importance, but the east and south shores are much indented. The highest points of the watershed from Costa Head to the Scapa shore are Milldoe to the north east of Isbister and Wideford Hill to the west of Kirkwall. There are also a few eminences towards the south-west, Ward Hill (88o ft.) in the parish of Orphir being the highest peak in the island. There are numerous lakes, some of considerable size and most of them abounding with trout. Kirkwall, the capital of the Orkneys, and Stromness are the only towns.
In Harray, the only parish in the Orkneys not trenched at some point by the sea, Norse customs have survived longer than else where in the group save in North Ronaldshay.
The antiquities of Pomona are of great interest. The examples of Pictish remains include broths, chambered mounds and weems, or underground dwellings afterwards roofed in. North-east of
Stromness, and within a mile of the stone circles of Stenness, stands the great barrow or chambered mound of Maeshowe. The tumulus has the form of a blunted cone, 30o ft. in circumference, and at a distance of 90 ft. from its base is encircled by a moat. The ground-plan shows that it was entered from the west by a passage, which led to a central apartment, the walls of which ended in a beehive roof. The barrow is variously ascribed to the Stone Age and to loth century Norsemen.
The stone circles forming the Ring of Brogar and the Ring of Stenness lie 41 m. N.E. of Stromness. The Ring of Brogar, once known as the Temple of the Sun, stands on a raised circular platform of turf, surrounded by a moat and a grassy rampart. The ring originally comprised 6o stones, varying from 9 to 14 ft.
in height, set up at intervals of 17 ft. Only 13 are now erect.
The Ring of Stenness—the Temple of the Moon of local tradition —is of similar construction. The Stone of Odin, the great mono lith, pierced by a hole at a height of 5 ft. from the ground, which figures so prominently in Scott's Pirate, stood 15o yd. to the north of the Ring of Stenness.