Friday Prayer Options in the West

3) If there is an area where enough eligible people are present, but access to that area is blocked from the outside due to a public or strategic benefit, the congregation will be sound provided the local people have unequivocal, unrestricted access to it. For example, in large prisons, military bases, or big airports which are in sufficiently large cities and always have at least 100 people — despite their restricted access granted to people outside — the Friday congregation will be permissible, subject to the preceding condition that all the people in that prison, factory, airport, or railway station have unrestricted access to the congregation.