Seedbanks, like most scientific collections, can never be imaged in total. But if you need an illustration of this concept, what would you focus on? The building, its location, a curator, some machinery, a small subset of the collection, or some other aspect?
Fig. 3 in R. C. Johnson’s 2008 article Gene Banks Pay Big Dividends to Agriculture, the Environment, and Human Welfare in PLoS Biology, takes the “small subset” approach and hints at storage, metadata and retrieval as well as administration more generally.
The figure is – like all PLoS content – available under a CC BY license and can thus be reused in any way if properly cited. Several Wikipedias – including the Danish and Indonesian ones – have chosen to do so in order to illustrate articles pertaining to seedbanks and related subjects. They all use a copy of Johnson’s Fig. 3 - Seedbank.jpg on Wikimedia Commons, which is thus today’s Open Access File of the Day:
Any other suggestions for a non-text representation of a seedbank?