The Amarguillo is a river in the centre of the Iberian Peninsula and a tributary of the Cigüela. It belongs to the Guadiana river basin. In modern times, it is dry during most of the year.

Description

The watercourse originates to the north of the Collado de la Mirla (in the Sierra de la Calderina[es], a subrange of the Montes de Toledo) within the Spanish municipality of Urda. Featuring a catchment area of around 563 km2, the river runs for 55 kilometers mostly in a west-east direction near the fringes of the Montes de Toledo. Historically, the river has been the site of multiple catastrophic floods, including the 1891 one, in which the river reached an estimated flow by Consuegra of 114 m3/s. It passes near the Spanish municipalities of Urda, Consuegra, Madridejos, and Camuñas. Also known as arroyo de Valdespino in its lower course, it discharges into the Cigüela in the province of Ciudad Real.