The castle of Bouka (Greek: Κάστρο της Μπούκας, from the Italian word bocca) was the first major Ottoman fortification of Preveza, in northwestern Greece.

[2] The date of the castle's construction is also mentioned in the Short Chronicle number 71.7: ἔκτισεν τὴν Πρέβεζαν ἐπὶ ἔτους ‚ςϡπς΄, "he fortified Preveza in the year 6986 [Anno Mundi]".

The construction of the castle at the mouth of the Ambracian Gulf was immediately recognized by Leonardo III Tocco, Count of Cephalonia, in a manuscript letter written on 31 March 1478, as a danger for the Republic of Venice.

[7] The castle was presumably strengthened by the Ottomans in 1486-87, as well as in 1495 in order to ward off the imminent danger from the West, due to the conquering plans of the French king Charles VIII, which, however, were eventually abandoned.

[2] When the great Ottoman traveler Evliya Çelebi visited Preveza, around 1670, he described Bouka as a castle guarded by a garrison of 250 soldiers, with narrow streets, and about 100 small houses without gardens, as well as a mosque constructed by Sultan Süleyman I (r. 1520-66).