On the western side of the Río Canímar bridge, 8km east of Matanzas, a road runs 1km down to a cove presided over by the four guns of this yellow-painted castle (1720). The castle is now a museum dedicated to the student leader Antonio Guiteras Holmes (1906–35), who founded the revolutionary group Joven Cuba (Young Cuba) in 1934.

After serving briefly in the post-Machado government, Guiteras was forced out by army chief Fulgencio Batista and shot on May 8, 1935. A bronze bust marks the spot where he was executed.