Question: The River Fiddich flows by which 15th-century tower in Moray, Scotland?

Context paragraphs:
Inverquharity Castle: Inverquharity Castle is a 15th-century tower house in Angus, Scotland.  It lies around 4.5 km north-east of Kirriemuir near the River South Esk.

Craigellachie, Moray: Craigellachie (Gaelic: "Creag Eileachaidh") is a small village in Moray, Scotland, at the confluence of the River Spey and River Fiddich (whose valley or glen gives its name to the famous Scotch whisky Glenfiddich), in walking distance of the town of Aberlour.

Lennoxlove House: Lennoxlove House is a historic house set in woodlands half a mile south of Haddington in East Lothian, Scotland.  The house comprises a 15th-century tower, originally known as Lethington Castle, and has been extended several times, principally in the 17th, 19th and 20th centuries.  The house is protected as a category A listed building, and is described by Historic Scotland as "one of Scotland's most ancient and notable houses."  The wooded estate is included on the Inventory of Gardens and Designed Landscapes in Scotland, the national listing of significant gardens.

Cardoness Castle: Cardoness Castle is a well-preserved 15th-century tower house just south west of Gatehouse of Fleet, in south west Scotland.  It was originally owned by the MacCullochs of Myreton.  They abandoned the castle in the late 17th Century, following the execution of Sir Godfrey McCulloch for the murder of a Clan Gordon neighbour.  It is now in the care of Historic Environment Scotland, and is a scheduled monument.

Sauchie Tower: Sauchie Tower, also known as Devon Tower, is a 15th-century tower house in Clackmannanshire, Scotland.  The tower is located by the village of Fishcross, 1 km north of Sauchie and 2.5 km north of Alloa, close to the River Devon.  It is protected as a Category A listed building, and as a Scheduled Ancient Monument.

Lemmington Hall: Lemmington Hall is an 18th-century country mansion incorporating a 15th-century tower house, situated near Edlingham, Northumberland, England.  It is a Grade II* listed building.  The original tower house built for the Beadnall family in the early 15th century was a four-storey construction which was reduced in height in the 17th century when Nicholas Fenwick ( Mayor of Newcastle 1720) converted the building into a country house.

River Fiddich: The River Fiddich (Scottish Gaelic: "Fiodhach / Abhainn Fhiodhaich" ) is a right bank tributary of the River Spey in northeast Scotland.  It rises on the eastern slopes of Corriehabbie Hill in Glenfiddich Forest and flows northeastwards beneath the A941 road, past Auchindoun Castle to a sharp bend adjacent to the A920 road where it turns westwards to flow to Dufftown.  The Fiddich is joined on the eastern edge of the town by the Dullan Water which drains Glen Rinnes.  Their combined waters then flow generally northwestwards, passing beneath the B9014 road near Balvenie Castle and then the A95 at Craigellachie immediately before meeting the Spey.

Dalzell House: Dalzell House is a historic house in Motherwell, North Lanarkshire, Scotland.  It is located to the south of the town, on the north bank of the River Clyde.  At its core is a 15th-century tower house, with extensive additions built during the 17th and 19th centuries.  In the 1980s the house was restored and divided for sale as eighteen private apartments, while the surrounding Dalzell estate is now owned by North Lanarkshire Council.  The house is protected as a Category A listed building, and the grounds are listed on the "Inventory of Gardens and Designed Landscapes in Scotland".

Margaret Marsh: Margaret Marsh is a hamlet and civil parish in the English county of Dorset.  It is situated in the Blackmore Vale in the North Dorset administrative district of the county, halfway between the towns of Shaftesbury and Sturminster Newton.  It is sited on Kimmeridge Clay close to a small tributary stream of the River Stour.  In the 2001 census the parish had a population of 60.  In 2013 the estimated population of the parish was 40.  The parish church has a 15th-century tower and 13th-century font, but the rest of the building was rebuilt in 1873.  For local government purposes the parish is grouped with the parishes of East Orchard and West Orchard, to form a Group Parish Council.

Auchindoun Castle: Auchindoun Castle is a 15th-century L-Plan tower castle located in Auchindoun near Dufftown in Moray, Scotland.

Supporting paragraphs: River Fiddich Auchindoun Castle
Answer: Auchindoun Castle