Going Cheap: One Castle!

Almería's Alcazaba was once put on the market by the City Hall. It must have been a bit strapped for cash when, in 1866, the castle and its 37 hectares of extension were put up for sale for 1,175 pesetas (seven euros), which even then, sounds a bit cheap.
The city wanted to expand in the direction of the castle and so the offer included the rule that anyone who bought it would have to demolish the hulk that crowned the hill behind Almería and haul away all the rubble. Tourism hadn't been invented yet and only a few nutters were enchanted by the historic or scenic value of the monument, described by Wiki as an XI Century fortified complex.
(The Alhambra in Granada was also ready for demolition more than once, and for Mojácar readers, their castle was demolished in its entirety in the nineteen forties and fifties).
The demolition clause proved the undoing of the sale, due to its prohibitive cost. Nevertheless, much of the old castle walls were successfully demolished in the late XIX Century.
The Alcazaba finally received protection as Monumento Histórico Artístico in June 1931.