Question: Cowie Water is south of which ruined fortress in Scotland?

Context paragraphs:
Luther Water: Luther Water is a generally southerly flowing river in Aberdeenshire, Scotland that discharges to the River North Esk; this watercourse rises in the Howe of the Mearns somewhat south of Drumelzie Forest.  Draining chiefly agricultural lands, this stream has a notable lack of turbidity and a pH level of approximately 8.26 measured near the Mains of Luther.  Turbidity has been measured at 70 centimetres by the Secchi disc protocol.  summer temperatures are approximately 16 degrees Celsius and electrical conductivity is 21 micro-siemens per centimetre.  Armouring of the stream bottom consists of small rounded stones varying typically from about one centimeter to four centimeters in diameter, some of which are quartzite in composition, leading to a golden-green effect in some locations.  Other nearby watercourses discharging to the North Sea include Cowie Water to the north.

Strumica Fortress: Strumica Fortress also known as the Czar's Towers is a ruined fortress in eastern Macedonia.  It overlooks the city of Strumica.  The fortress was built in the 5th century, although the site itself dates from the 1st century BC.

Cowie Castle: Cowie Castle is a ruined fortress in Aberdeenshire, Scotland.  The site lies at the northern end of Stonehaven on the North Sea coast.  To the immediate south is the Cowie Bridge crossing of the Cowie Water.  Evidence of prehistoric man exists in the vicinity dating to the Iron Age in the form of ring cairns.

Cowie Bridge: Cowie Bridge is a roadway bridge across the Cowie Water in Stonehaven, Scotland near the river's mouth at the North Sea.  This construction is a listed historical structure in Aberdeenshire.  Historically the area in the vicinity of the Cowie Bridge site has been an old fishing village known as Cowie Village.  Between the Cowie Bridge and the North Sea, a new pedestrian bridge is planned, which will also support a new pipeline structure.  The site of Cowie Bridge is approximately the point of the southern terminus of the Causey Mounth trackway, which was the only available medieval route crossing the coastal Grampian Mountains northerly by way of Muchalls Castle and Gillybrands.

Allardice Castle: Allardice Castle (also spelled Allardyce) is a sixteenth-century manor house in Kincardineshire, Scotland.  This monument is occupied by the Cowie family and is approximately 1.5 kilometres northwest of the town of Inverbervie.  The Bervie Water flows around Allardice Castle on both sides.  Allardice may be viewed as one of a chain of coastal castles; to the north are Dunnottar Castle (ruined), Fetteresso Castle, Cowie Castle (ruined) and Muchalls Castle.  The castle is a category A listed building.

Koshoy Korgon: Koshoy Korgon or Qoshoy Qorgon (Kyrgyz: Кошой Коргон ] ) is a ruined fortress of uncertain date located in At-Bashy District, Kyrgyzstan.  The structure, which consists of walls made of mud enclosing a large area and is identified as a korgon ("fortress", not to be confused with a kurgan), is immediately to the southeast of Kara-Suu village, and a little ways west of At-Bashy village.  It is named after Qoshoy baatyr, one of Manas's generals, who is thought to have been a catalyst for its construction.  There is an on-site museum for tourists that is rarely open.

Burn of Monboys: Burn of Monboys is a stream that rises in the Mounth, or eastern range of the Grampian Mountains, northwest of Stonehaven and south of Netherley, Aberdeenshire, Scotland.  Monboys Burn is a tributary to the Cowie Water.

Cowie Water: The Cowie Water (Scottish Gaelic: "Uisge Chollaidh" ) is a river rising in the Grampian Mountains in Aberdeenshire, Scotland that discharges to the North Sea in the northern part of Stonehaven.  south of the ruined Cowie Castle.  Tributaries of the Cowie Water include the Burn of Monboys, which drains the area to the north, in which the archaeological site Raedykes Roman Camp is situated; and Cowton Burn.

Rickarton House: Rickarton House is a 19th-century country house in Kincardineshire, Scotland.  It lies approximately three and a half miles northwest of Stonehaven in the former county of Kincardineshire.  The house is situated on the north banks of the Cowie Water slightly upstream of the confluence with Cowton Burn.  Rickarton is a category B listed building.  Rickarton House was constructed in the first decade of the 19th century for William Rickart Hepburn.  He commissioned the City Architect of Aberdeen, John Smith, to undertake the work.

ǁKhauxaǃnas: ǁKhauxaǃnas (Khoekhoegowab: "passively defend people from an enemy", Afrikaans / Dutch name Schans Vlakte: "sconce valley") is an uninhabited village with an ancient ruined fortress in south-eastern Namibia, east of the Great Karas Mountains.  It is the oldest systematically designed and built structure in Namibia, pre-dating all buildings erected by Europeans.  Built at the end of the 18th century, most likely between 1796 and 1798 by Klaas Afrikaner and his two sons Jager and Titus, ǁKhauxaǃnas served as a hidden retreat and a fortress to fend off possible pursuits by Cape authorities.  The Orlam Afrikaner tribe left the place in the 1820s but it continued to be inhabited by the Veldschoendragers (ǁHawoben) tribe until the mid-19th century.

Supporting paragraphs: Cowie Water Cowie Castle
Answer: Cowie Castle