Novi Zrin (Hungarian: Zrínyiújvár or Új-Zrínyivár) was a fortress of the Zrinski (Zrínyi in Hungarian) noble family built near the Donja Dubrava village in the northernmost part of Croatia (at the border village of Őrtilos in Hungary) on the mouth of river Mura into Drava between 1661 and 1664.

Its purpose was to prevent the Ottoman military forces from advancing further into Croatia. The Ottomans attacked it several times from 1662 to 1664, but did not manage to conquer it. Finally, at the beginning of June 1664 a large Ottoman army, numbering up to 100,000 men, led personally by the Grand Vizier Köprülü Fazıl Ahmed Pasha, besieged it and destroyed on 7 July 1664.

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  Memorial obelisk on the place at the Mura River where the castle once was
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  350th Anniversary commemoration of the destruction of the castle
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  Programme booklet of the International scientific conference concerning the 350th anniversary of the death of Nikola VII Zrinski and the fall of Novi Zrin Castle (Donja Dubrava, Međimurje County, 5 July 2014)
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  Scene of the International scientific conference held in Donja Dubrava on 5 July 2014
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  Illustration of one of the battles in 1663 when Ottomans failed to capture the fort.

• First Battle of Novi Zrin
• Second Battle of Novi Zrin
• Siege of Novi Zrin (1664)
• Nikola VII Zrinski

• Petrić, Hrvoje; Feletar, Dragutin; Feletar, Petar (2001). Novi Zrin (1661-1664). Zagreb: Meridijani. ISBN 953-6235-84-6.

• Novi Zrin base drawing
• Novi Zrin look and history
• Novi Zrin draft and memorial obelisk