Catalogue for the installation Signatures that French artist Christian Boltanski created specifically for the Aljub space of Es Baluard. The artist retrieves the marks that were made on the stones used to build the Baluard de Sant Pere, the site of the Es Baluard museum, by the stonemasons in the 17^th century, thus recovering the memory of these anonymous workers. Conceived as signs of light and accompanied by the echo of heartbeats that simultaneously sound like hammer strokes, they emerge intermittently from the fog, continuing with some of the axes on which Boltanski’s work is developed: the archive, memory and death. The catalogue contains the images from the installation and texts by art critic Fernando Huici on the figure and work of Boltanski and historian Aina Pascual, as well as a study of the history of the walls and the remains of the bastion of Sant Pere.