Castillo de Olite was a cargo steamship that was launched in 1920 in the Netherlands as Zaandijk. She passed through a series of Dutch and Soviet owners, and at different times was renamed Zwartewater, Postyshev and Akademik Pavlov. In 1938 the Spanish Nationalist Navy captured her and renamed her Castillo de Olite. In the last days of the Spanish Civil War she was sunk with great loss of life while serving as a troop ship.