The Park Avenue Discotheque was a huge dance club in downtown Milwaukee, with a primarily "straight" clientele every night except Sunday night, which was reserved as "gay night" and used the name "Sundays" on that day. (A membership card stated "John and Dave present 'Sundays' / 'a very private affair'.") Situated in a landmark red stone building just north of the expressway spur for I-794, the building had a commanding presence.

The interior of the club was expensively decorated, and had a most impressive dance floor in the center of the building. Chairs and stools were situated on all sides (with the main bar along the entire south wall), and the dance floor area itself rose two floors in height. Patrons could move between the first and second floors at will, dancing themselves on the first floor, or watching the dancing from the second level from balcony railings surrounding the dance area. The second level had its own bars, but also some quieter areas for relaxing and talking (including a windowed alcove fitted in the turret, in the southwest corner, above the entrance).

More information about this business is welcomed from anyone who can contribute it.