Kryal Castle is a replica medieval castle located eight kilometres east of Ballarat, Australia, at Leigh Creek, just north of Dunnstown, in the foothills of Mount Warrenheip.
 The castle's name derives from the first initial and surname of its builder, Keith Ryall, who had made his fortune selling body armour.
 Construction began in 1972, and the attraction was opened to the public in 1974.
William I (Willem Frederik, Prince of Orange-Nassau; 24 August 1772 – 12 December 1843) was a Prince of Orange and the first King of the Netherlands and Grand Duke of Luxembourg.
Alice Curtayne (1898–1981) was an Irish author and lecturer.
 She was born on 6 November 1898, 2 Upper Castle St, Tralee, Co.
 Kerry.
 She was a daughter of John Curtayne, carriage builder, or coach builder, of Castle St, Tralee, by his wife Bridget Mary O'Dwyer.
Tiffany Castle is a landmark in the historic Pendleton Heights neighborhood in Kansas City, Missouri, United States.
 The castle sits on the bluffs overlooking the East Bottoms and the Missouri River below.
 The castle gets its name from its builder and first owner, Dr. Flavel B. Tiffany whose love of the castles in Europe spurred his desire to build one of his own in Kansas City.
Kinlochaline Castle is a 12th-century Scottish fortress on the Ardtornish estate in Morvern in the Highland council area.
 It is also known as Caisteal an Ime (Scottish Gaelic for "Castle of Butter") because a Lady of Clan MacInnes, Dubh Chal (Lady of the Black Veil), is said to have paid the builder with butter equal to the volume of the castle.
John Lefurgey (March 17, 1824 – May 5, 1891) was a merchant, ship builder and political figure in Prince Edward Island.
 He represented 5th Prince in the Legislative Assembly of Prince Edward Island from 1870 to 1890 as a Conservative member.
Walferdange Castle (French: "Château de Walferdange" ), located in the small town of Walferdange in central Luxembourg, dates from 1824 when William I of the Netherlands who was also Grand Duke of Luxembourg built it as a stud farm.
 It is now part of the University of Luxembourg.
Osborne House is a former royal residence in East Cowes, Isle of Wight, United Kingdom.
 The house was built between 1845 and 1851 for Queen Victoria and Prince Albert as a summer home and rural retreat.
 Prince Albert designed the house himself in the style of an Italian Renaissance palazzo.
 The builder was Thomas Cubitt, the London architect and builder whose company built the main façade of Buckingham Palace for the royal couple in 1847.
 An earlier smaller house on the site was demolished to make way for a new and far larger house, though the original entrance portico survives as the main gateway to the walled garden.
Amalia Maria da Gloria Augusta (Ghent, 20 March 1830 — Walferdange, Luxembourg, 1 May 1872), Princess of Saxe-Weimar-Eisenach, was the first wife of Prince Henry of the Netherlands, son of king William II of the Netherlands.
James Yeo (October 31, 1827–February 13, 1903) was a merchant, ship builder, ship owner, and Canadian Member of Parliament for Prince Edward Island, representing Prince County beginning in 1873 when Prince Edward Island joined Canadian Confederation and serving until 1891.

Question: Where was the builder of Walferdange Castle a Prince of?
Answer: Orange