Miren Castle (Slovene: Mirenski grad, also known as Grad 'castle' and Naša Gospa pod Krasom 'Our Lady beneath the Karst'; Italian: Grado di Merna or Castello di Merna) is an elevation above the settlement of Miren near Nova Gorica, in southwest Slovenia. Its Slovene name reflects the fact that the hill was once occupied by a castle; it is currently dominated by a collection of ecclesiastical buildings.
Over the centuries, a series of churches have occupied the site. The first recorded was the Church of Our Lady, built in 1488, rebuilt in 1753, and destroyed on 30 May 1914. Between 1700 and 1756, Grad was inhabited by hermits. The summit of Grad is now dominated by a monastic church dedicated to Our Lady of Sorrows (Slovene: cerkev Žalostne Matere božje). It was built in 1886, and was completely destroyed and rebuilt during and after each World War. In 1958, its interior was decorated with frescoes by Tone Kralj. The entrance gate bears the inscription Ite in domum Matris Vestræ 'Go into the house of your mother'. It is still a pilgrimage destination.