Only by truly crossing the border, one changes from an outsider to an insider.
In some occasions one has to move through a notable entrance to set foot in the area off limits for outsiders.
A rite of migration symbolising the passage, emphasises the border. The grand and highly symbolic entrance, although open to some, underpins the closeness of the organisation and the impenetrability of the holy grounds of the inside.
This design features of a great entree should be carefully managed and even then it can be harmful for the organisation.