This sub-series comprises 9 boxes of loose postcards, featuring heritage sites, architectural features, sculpture, churches, landscapes, relics, dig sites, ruins, archaeological finds, and antiquities throughout. Postcards are generally arranged geographically (i.e., by country or continent; postcards from and/or depicting different African and Asian countries have, rather reductively, been grouped together by continent at an earlier time).

The postcards in this collection feature significantly fewer inscriptions than those in ES-PC-01, Strong's postcard albums; they were possibly part of her own reference collection.