216.6 Entrances. Where not all entrances comply with 404, entrances complying with 404 shall be identified by the International Symbol of Accessibility complying with 703.7.2.1. Directional signs complying with 703.5 that indicate the location of the nearest entrance complying with 404 shall be provided at entrances that do not comply with 404.

35.163(b) "A public entity shall provide signage at all inaccessible entrances to each of its facilities, directing users to an accessible entrance or to a location at which they can obtain information about accessible facilities. The international symbol for accessibility shall be used at each accessible entrance of a facility."

Notice that, for public entities under Title II, the language of the regulations is stricter than the Standards.  The regulations require the ISA at ALL accessible entrances, not just at accessible entrances in facilities that have some inaccessible entrances.

Provide the ISA at all accessible entrances in all public entity facilities.