The landscape of the Borgue area is defined by the underlying geology. The rocks under Borgue are sandstones and siltsones dating from the Silurian period around 430 million years ago. These rocks were folded and tilted by tectonic plate movements and are now almost vertical, oriented south-west to north-east. This creates ridges of land that run inland from the coast with rocky outcrops on top of the ridges. Where the rocks meet the sea, there are indented bays with sheltered beaches as seen at Brighouse and Carrick.
There are some intrusions of igneous rocks through the sedimentary rocks. One of the best examples is at Shoulder o’ Craig near Nun Mill Bay. This is the remains of a volcanic vent with outcrops of breccia and dykes of basalt and lamprophyre. These are described in detail along with other local geological features in the Kirkcudbright Geology Excursion article.
Roughly two thirds of the land in the parish is arable, the remaining third being woodland and rough pasture. The undulating landscape is unusual and interesting, consisting of small fields bounded by dry stane dykes, with characteristic rocky outcrops or knowes. The fertile areas between the knowes offer excellent grazing for dairy cattle, providing milk, and the knowes are often rich in plant and insect life, providing honey. The quality of both the milk and the honey that comes from Borgue is locally known to be unrivalled. Many of the coastal trees are sculpted into windswept shapes by the prevailing south-westerlies.
Many of the dry stane dykes of the Borgue Area are built in the ‘Galloway Style’. This consists of a lower double wall surmounted by an upper layer of large slabby blocks. There are some good examples of this style of walling that can be seen from the coast road near Kirkandrews and from the road from Knockbrex to Barharrow.
Borgue has a few streams that run down to the see but no rivers of any size. The Goat Strand runs from Knockewan to Knockbrex where it meets the Plunton Burn coming down from Plunton Castle and is then channeled through the grounds of Knockbrex House. The Pulwhirrin Burn is the largest stream in Borgue. It comes down from the Glenterry/Conchieton area then runs past Mill of Plunton, Plunton House and Rattra Farm before meeting the sea at Kirkandrews Bay. The area between Muncraig and Cairniehill is drained by a small, unnamed stream that runs into Ringdoo Bay. Another unnamed stream runs from the farm lands around Culraven down to the sea at Brighouse Bay. The Borgue parish area is bounded on the east side by the Mill Hall Burn that meets the sea at the Dhoon beach.
The coastline of Borgue is designated as a Site of Special Scientific Interest (SSSI) for its geological formations and seabird population.
Going from east to west, the popular beach at the Dhoon in Nun Mill Bay has a large car park and public toilets. The coast then becomes rocky along to the large, muddy Ross Bay. Between Ross Bay and Brighouse Bay, the Mull of Ross features some large steep cliffs. Brighouse Bay is a popular bathing an recreational beach with parking and toilet facilities. The coast from Brighouse to Kirkandrews is mostly rocky and features several large sea caves and a few pinnacles. Between Kirkandrews and Carrick there are a number of secluded, sandy bays, separated by rocky headlands.
There are several islands off the Borgue coast. Little Ross Island overlooks the entrance to Kirkcudbright Bay and has a lighthouse. The lighthouse was the scene of a notorious murder in 1961. The Isles of Fleet are found on the south side of the Fleet estuary. They are called Barlocco Isle, Ardwall Isle and the Murray Isles. Ardwall and Barlocco Isles can be accessed on foot at low spring tides but beware of the rapidly rising incoming tide. Ardwall Island has the remains of an old chapel at the landward side (see History section for more information) and a holiday cottage that is still in use at the seaward side. The Murray Isles are owned by the National Trust and are breeding grounds for sea birds and seals.
There are over 20 farms in the Borgue area. Most of these are devoted to dairy, beef and sheep production. There are a few small farms that sell their produce locally and some farms are diversifying into supporting tourism, providing campsites, holiday cottages/lodges and a range of activities.