Holy informational rabbit hole, Batman! Wikipedia has a page that is a List of lists of lists.
This article is a list of articles comprising a list of things that are themselves lists of things, such as the lists of lists listed below.
Inception horn! Includes such lists of lists as Lists of fictional Presidents of the United States, Ranked lists of Chilean regions, Lists of black people, and Lists of nuclear disasters and radioactive incidents. (via @sampotts)