"Arapiles", названих на честь пагорбів - важливої позиції під час Битви при Саламанці, was built by Green at their shipyard in Blackwall, London. She was laid down in June 1861 as an unarmored frigate, but began her conversion into an ironclad in August 1862 when roughly of armor was added. The ship was launched on 17 October 1864 and completed the following year.