The tower has a square floor and appreciable proportions. It was totally built with a garden wall of excellent execution. Over the centuries, the tower became a part of the buildings from a farming exploitation that nowadays has also disappeared. The origins of Alonso Navarro go back to the 12th century; however, a date of later construction cannot be rejected. The tower, considered already from the Christian time, is probably related to the defence policy and the territory control practised by the Order of Santiago.
The fortification is declared a heritage of Cultural Interest (BIC) by the Second Additional Provision of Law 16/1985, from June 25th of the Spanish Historical Heritage. Recently, a superior section, provided with openings divided and topped by attachments that seem to imitate battlements, has being joined firmly.