The Rhön Mountains (German: "Die Rhön" (   )) are a group of low mountains (or "Mittelgebirge") in central Germany, located around the border area where the states of Hesse, Bavaria and Thuringia come together.
 These mountains, which are at the extreme southeast end of the East Hesse Highlands ("Osthessisches Bergland"), are partly a result of ancient volcanic activity.
 They are separated from the Vogelsberg Mountains by the river Fulda and its valley.
 The highest mountain in the Rhön is the Wasserkuppe (950.2 m ) which is in Hesse.
 The Rhön Mountains are a popular tourist destination and walking area.
Prince Friedrich of Hesse and by Rhine (Friedrich Wilhelm August Victor Leopold Ludwig; 7 October 1870 – 29 May 1873) was the haemophiliac second son of Louis IV, Grand Duke of Hesse, and Princess Alice of the United Kingdom, one of the daughters of Queen Victoria.
 He was also a maternal great-uncle of Prince Philip, Duke of Edinburgh through his eldest sister Princess Victoria of Hesse and by Rhine.
Princess Irene of Hesse and by Rhine ("Irene Luise Marie Anne, Princess of Hesse and by Rhine", 11 July 1866 – 11 November 1953) was the third child and third daughter of Princess Alice of the United Kingdom and Louis IV, Grand Duke of Hesse and by Rhine.
 Her maternal grandparents were Queen Victoria and Prince Albert of Saxe-Coburg and Gotha.
 Her paternal grandparents were Prince Charles of Hesse and by Rhine and Princess Elizabeth of Prussia.
 She was the wife of Prince Henry of Prussia, a younger brother of Wilhelm II, German Emperor and her first cousin.
 The SS "Prinzessin Irene", a liner of the North German Lloyd was named after her.
The Apennines or Apennine Mountains ( ; Greek: Ἀπέννινα ὄρη ; Latin: "Appenninus" or "Apenninus Mons "—a singular used in the plural; Italian: "Appennini" ] ) are a mountain range consisting of parallel smaller chains extending  1200 km along the length of peninsular Italy.
 In the northwest they join with the Ligurian Alps at Altare.
 In the southwest they end at Reggio di Calabria, the coastal city at the tip of the peninsula.
 Since the year 2000 the Environment Ministry of Italy, following the recommendations of the Apennines Park of Europe Project, has been defining the Apennines System to include the mountains of north Sicily, for a total distance of 1500 km .
 The system forms an arc enclosing the east side of the Ligurian and Tyrrhenian Seas.
Alexander Frederick, Landgrave of Hesse (German: "Alexander Friedrich Wilhelm Albrecht Georg Landgraf von Hessen" 25 January 1863, Copenhagen – 26 March 1945) was a Hesse-Kassel and Prussian Prince.
 He was the son of Prince Frederick William of Hesse-Kassel and Princess Anna of Prussia.
 From 1888–1925 he was Head of the House of Hesse, but abdicated his position to his brother Prince Frederick Charles of Hesse.
 He was visually handicapped from birth, and this, in addition to his morganatic marriage, played a part in his decision to abdicate.
The Electorate of Hesse was abolished in 1866 when it was annexed by the Kingdom of Prussia, while the Grand Duchy of Hesse and by Rhine came to an end in 1918.
 Like most former German realms of the Holy Roman Empire the succession in Hessian lands was semi-Salic, with the nearest female kinswoman of the last male inheriting the crown upon extinction of the dynasty in the male line.
 The current pretender to both Hessian thrones is Donatus, Landgrave of Hesse, from the electoral line of the family, which inherited its claim to the grand duchy following the death of Prince Louis of Hesse and by Rhine in 1968.
 Donatus became head of the House of Hesse on the death of his father, Prince Moritz, in 2013.
 Landgrave Donatus is the titular Grand Duke and Elector of Hesse.
Moritz, Prince and Landgrave of Hesse ("Moritz Friedrich Karl Emanuel Humbert" 6 August 1926 – 23 May 2013) was the son of Prince Philip, Landgrave of Hesse, and the head of the House of Brabant and the German House of Hesse.
The Battenberg family was formally a morganatic branch of the House of Hesse-Darmstadt, rulers of the Grand Duchy of Hesse in Germany.
 The first member was Julia Hauke, whose brother-in-law Grand Duke Louis III of Hesse created her "Countess of Battenberg" with the style "Illustrious Highness" (H. Ill.H.) in 1851, at her morganatic marriage to Grand Duke Louis' brother Prince Alexander of Hesse and by Rhine, and elevated her title to "Princess of Battenberg" with the style "Serene Highness" (HSH) in 1858.
 The name "Battenberg" was last used by her youngest son, Prince Francis Joseph of Battenberg, who died childless in 1924.
 Most members of the family, residing in the United Kingdom, had renounced their German titles in 1917, due to rising anti-German sentiment among the British public during World War I, and changed their name to "Mountbatten", an anglicised version of Battenberg.
 The name Battenberg refers to the town Battenberg, Hesse.
Princess Christina Margarethe of Hesse (German: "Prinzessin Christina Margarethe von Hessen" ; 10 January 1933 – 22 November 2011) was the eldest daughter of Prince Christoph of Hesse and Princess Sophie of Greece and Denmark.
 From 1956 to 1962, she was married to Prince Andrew of Yugoslavia, with whom she had two children.
 Her second marriage to Robert Floris van Eyck, a Dutch artist based in London, lasted from 1962 to 1986.
Christoph Ernst August of Hesse (Frankfurt, 14 May 1901 – Apennine Mountains near Forlì, 7 October 1943) was the fifth son of Prince Frederick Charles of Hesse and Princess Margaret of Prussia.
 He was a German SS officer killed accidentally during World War II.

Question: What country did Prince Christoph of Hesse die in?
Answer: Italy