The Arsenal is the most striking structure among the ones in Trabzon. According to the Yıldız Palace records, it was constructed in 1305 in Islamic Calendar (1887 in Gregorian calendar). Both the inscription and the signature of Sultan Abdülhamit II over its door conﬁrms this date. The Arsenal, with a 25-40 m diameter, includes two circular structures; one inside of the other. The inside one is four storied whereas the outer is three storied.