Question: In what northern country was the Battle of Champions fought between Ackergill Tower and Girnigoe Castle?

Context paragraphs:
Northern Country Party: The Northern Country Party was an Australian political party operating in the state of Queensland during the 1920s.  It had a separate organisation from the wider Country Party in the state, although the two were connected.  In 1923 its organisation merged into the Country Party, although its two members of the Queensland Parliament instead became members of the new Queensland United Party.

Battle of Champions: The Battle of Champions was a trial by combat fought in 1478 or 1464 between two Scottish clans, Clan Gunn and Clan Keith.  It took place at the chapel of St Tears (St Tayre) on the coast north of Wick in Caithness, between Ackergill Tower and Girnigoe Castle.  It was arranged to settle a dispute with a battle between twelve men on horseback on either side.  However, the Keiths arrived with two men on each of their twelve horses, and massacred the 12 Gunns.  The clans finally signed a treaty of friendship in 1978, ending the feud after 500 years.

Black River (Victoria): The Black River, an inland perennial river of the Goulburn Broken catchment, part of the Murray-Darling basin, is located in the lower South Eastern Highlands bioregion and Northern Country/North Central regions of the Australian state of Victoria.  The headwaters of the Black River rise on the northern slopes of the Yarra Ranges and descend to flow into the Goulburn River within the Yarra Ranges National Park.

Ackergill Tower: Ackergill Tower (or Ackergill Castle) is located north of Wick, Caithness, in northern Scotland.  It was built in the early 16th century, and is a category A listed building.  Ackergill is currently operated as an events and wedding venue by AmaZing Venues.

Big River (Goulburn River, Victoria): The Big River, an inland perennial river of the Goulburn Broken catchment, part of the Murray-Darling basin, is located in the lower South Eastern Highlands bioregion and Northern Country/North Central regions of the Australian state of Victoria.  The headwaters of the Big River rise on the northern slopes of the Yarra Ranges and descend to flow into the Goulburn River within Lake Eildon.

Michael Carbajal vs. Humberto González: The Michael Carbajal vs. Humberto González fight was an encounter that made professional boxing history in many ways.  While this pair of world junior flyweight champions fought three times, their first fight is the one that writers and fans usually remember with fondness.

Bilad al-Sham: Bilad al-Sham (Arabic: بلاد الشام‎ ‎ , "northern country", i.e. Syria) was a Rashidun, Umayyad and later Abbasid Caliphate province in the region of Syria.  It incorporated former Byzantine territories of the Diocese of the East, organized soon after the Muslim conquest of Syria in the mid-7th century, which was completed at the decisive Battle of Yarmouk.

Acheron River (Victoria): The Acheron River , a minor inland perennial river of the Goulburn Broken catchment, part of the Murray-Darling basin, is located in the lower South Eastern Highlands bioregion and Northern Country/North Central regions of the Australian state of Victoria.  The headwaters of the Acheron River rise on the northwestern slopes of the Yarra Ranges, below The Knobs and descend to flow into the Goulburn River near Alexandra .

Yea River: The Yea River, an inland perennial river of the Goulburn Broken catchment, part of the Murray-Darling basin, is located in the lower South Eastern Highlands bioregion and Northern Country/North Central regions of the Australian state of Victoria.

Solar energy in Finland: Solar energy in Finland is used primarily for water heating and by the use of photovoltaics to generate electricity.  As a northern country, summer days are long and winter days are short.  Above the Arctic Circle, the sun does not rise some days in winter, and does not set some days in the summer.  Due to the low sun angle, it is more common to place solar panels on the south side of buildings instead of on the roof.  Mounting them vertically reduces the average output by 22% from mounting at a 60° angle.

Supporting paragraphs: Battle of Champions Ackergill Tower
Answer: Scotland