Osma Castle is situated next to the town of El Burgo de Osma, in the western part of the province of Soria in Spain.On a hill between the rivers Ucero and Avion, close to the ancient Roman city of Uxama and dominating the today humble, but formerly important, town of Osma, lie the remains of this once strong castle. It once possessed three walled enclosures of which nowadays some remains can be seen. The highest inner enclosure makes up the present castle, with remains of a keep and other buildings. Along the outline of the lowest and largest outer enclosure, running down the slope of the hill, next to the riverbank, stands a ruined tower called Torre del Aqua (Tower of the Water). It is constructed, as are some parts of the castle, with building materials taken from the ruins of nearby Uxama.
 
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