Dualities involving ensembles of theories represent a fascinating class of holographic correspondences. The inclusion of wormholes into a theory naturally motivates the study of ensembles, but doing so leads to many puzzles from the viewpoint of string theory. In this talk, I will discuss holographic dualities involving ensembles of 2D Narain conformal field theories. The bulk dual of such an ensemble is an Abelian Chern-Simons theory, but features a sum over 3D geometries. Generalizations of this correspondence lead to emergent ensemble symmetries – global symmetries that appear after averaging over the ensemble and are the vestiges of T-duality in the CFT. These symmetries are intimately related to the anyon data and 0-form symmetries of the bulk Chern-Simons theories. I will also discuss the relation of these emergent global symmetries with recent ideas in quantum gravity, and furthermore generally discuss the role of ensemble averaging in standard holography, the landscape, and the swampland. If you are planning to attend, please send and email to pietro.benetti_genolini@kcl.ac.uk or alan.rios_fukelman@kcl.ac.uk so your name is added to the participants list in order to grant you access to the building.