28 CFR § 540.41 - Visiting facilities.
The Warden shall have the visiting room arranged so as to provide adequate supervision, adapted to the degree of security required by the type of institution. The Warden shall ensure that the visiting area is as comfortable and pleasant as practicable, and appropriately furnished and arranged. If space is available, the Warden shall have a portion of the visiting room equipped and set up to provide facilities for the children of visitors.
(b) Institutions of medium and high security levels, and administrative institutions may establish outdoor visiting, but it will always be inside the security perimeter and always under supervision of staff.