Grabusa, long regarded as an impregnable fortress, was surrendered in 1692, Suda (where the flags of Turkey and the four protecting powers are now hoisted) and Spinalonga in 1715.
Impregnable Malta surrenders without a shot; his most reckless schemes are crowned with success.
Hitherto Venice had enjoyed the advantages of isolation; the lagoons were virtually impregnable; she had no land frontier to defend.
The city itself, with its fortifications extending to the port of Peiraeus, was impregnable to a land attack.
The rich low-lying lands of Morganwg and Gwent were thus firmly occupied, nor were they ever permanently recovered by the Welsh princes; and such natives as remained were kept in subjection by the almost impregnable fortresses of stone erected at Caerphilly, Cardiff, Cowbridge, Neath, Kidwelly and other places.