Arcana Coelestia #3271
3271. 'In their fortified places' means the internal aspects. This is clear from the meaning of 'fortified places' as the internal aspects of faith, here of the Church, since they have reference in particular to gentiles, who do not possess the truth of faith but rational and natural truth. These truths are called 'fortified places' when the truths of faith are called 'cities'. In the original language these expressions which mean villages and fortified places also mean courts and palaces; and courts similarly are the external aspects of the Church, palaces the internal.
Revelation 21:12
12
having a great and high wall; having twelve gates, and at the gates twelve angels; and names written on them, which are the names of the twelve tribes of the children of Israel.