Question: Isabella Kelly was born at a ruined castle characterized as one of the most isolated fortifications in Britain by who?

Passages:
Scharfenstein Castle (German: "Burg Scharfenstein" ), a ruined castle near the town of Kiedrich in Hesse, Germany, was part of the Bishopric of Mainz’s border fortifications.  It was erected in 1160 under Christian I (Archbishop of Mainz). Abergairn Castle is a ruined castle, dating from the 17th century, about one mile north of Ballater, Aberdeenshire, Scotland.  It is built on the top of an isolated kame, at the north east of the entrance to Glen Gairn. The Château de Longwy is a ruined castle, incorporated into the town's fortifications, in the "commune" of Longwy in the Meurthe-et-Moselle "département" of France. Clun Castle is a ruined castle in the small town of Clun, Shropshire.  Clun Castle was established by the Norman lord Robert de Say after the Norman invasion of England and went on to become an important Marcher lord castle in the 12th century, with an extensive castle-guard system.  Owned for many years by the Fitzalan family, Clun played a key part in protecting the region from Welsh attack until it was gradually abandoned as a property in favour of the more luxurious Arundel Castle.  The Fitzalans converted Clun Castle into a hunting lodge in the 14th century, complete with pleasure gardens, but by the 16th century the castle was largely ruined.  Slighted in 1646 after the English Civil War Clun remained in poor condition until renovation work in the 1890s. Inch Castle is a ruined castle located on the southern tip of Inch Island in County Donegal, Ireland.  The castle was constructed around 1430 by the Gaelic Irish lord Neachtain O'Donnell for his father-in-law Cahir O'Doherty.  The O'Doherty's were the dominant family on the nearby peninsula of Inishowen and had close links with the O'Donnells.  It came to form part of the defensive network of O'Doherty fortifications designed to protect them from rival clans and to overawe those who accepted their overlordship. Castillo de Tabernas is a ruined castle on the outskirts of the municipality of Tabernas, Almería province, in the autonomous community of Andalusia, Spain.  It was built in the 11th century during the time of Arab domination.  It is of Moorish style and is situated on top of a hill.  When it was built, it occupied the entire hill, though currently only a part is preserved.  In 1993, it was declared a Bien de Interés Cultural monument.  During the siege of Almeria, Ferdinand and Isabella ensconced themselves in the castle. The Wegelnburg is a ruined castle near Schönau in the Palatinate Forest in Rhineland-Palatinate, Germany, near the border with France.  Its location is at a height of 572m, making it the highest ruined castle in the Palatinate Forest. Cairnburgh Castle is a ruined castle that is located on the islands of Cairn na Burgh Mòr and Cairn na Burgh Beag, Argyll and Bute, Scotland.  These islands are at the northern extremity of the Treshnish Isles at the mouth of Loch Tuath, Mull north of Iona.  1991's "The Changing Scottish Landscape" characterizes it as "one of the most isolated fortifications in Britain...[and] also one of the strangest." Isabella Kelly, née Fordyce, also Isabella Hedgeland (born at Cairnburgh Castle in the Scottish Highlands and baptised on 4 May 1759 – died on 25 June 1857 in London) was a Scottish novelist and poet. Schauenberg is a hill and ruined castle near Turbenthal, canton of Zurich, at 892m.  There were fortifications since the Iron Age, and since the early 13th century, there was a wooden structure, in the 1250s extended to a massive keep.  The fortress was destroyed in 1344.  From 1622, Zurich maintained a system of beacons as a warning system, and signals from Schauenberg could be seen at Schnabel (Albis), Pfannenstiel, Tämbrig (above Hermatswil), Uetliberg, Lägern, Zürichberg, Mörsburg, Kyburg, Stammheimerberg and even Hohenklingen.

Supporting sentences:
Isabella Kelly, née Fordyce, also Isabella Hedgeland (born at Cairnburgh Castle in the Scottish Highlands and baptised on 4 May 1759 – died on 25 June 1857 in London) was a Scottish novelist and poet. Cairnburgh Castle is a ruined castle that is located on the islands of Cairn na Burgh Mòr and Cairn na Burgh Beag, Argyll and Bute, Scotland.  1991's "The Changing Scottish Landscape" characterizes it as "one of the most isolated fortifications in Britain...[and] also one of the strangest."