Charles H. Spurgeon on Psalms 144:2

My high tower. Such towers were erected on mountains, on rocks, or on the walls of a city, and were regarded as safe places mainly because they were inaccessible. So the old castles in Europe, —as that at Heidelberg, and generally those along the Rhine, —were built on lofty places, and in such positions as not to be easily accessible. —Albert Barnes.