The closest is Ganja Fortress, 1 km south-west of the city centre; the most famous is Palace of Shaki Khans — #576 of 8,133 worldwide — 91 km north-east. The oldest dated site in the circle is Khornabuji Castle, founded c. 250 BC.
The 100 km circle reaches into 3 countries — Azerbaijan (17), Armenia (1), Georgia (1).