I am starting to configure Zenphoto to display an archive of old photographs, and am looking for a Theme that will display Title and Description with each photo, whether an Album, thumbnail or a full size image. I'm struggling to find one, as most Themes seem not to do this. Rail Geelong (https://www.railgeelong.com/gallery/) is nearest to what I'm looking for, but the Theme does not appear on the Zenphoto website.
Also, the descriptive information relating to each photo is currently stored in spreadsheets and tables. Is there a way to do a bulk import of this information into Zenphoto after the photos have been uploaded, maybe into the Custom Data box for each photo, from where I can edit it into something better as the Title and Description? Thanks.

1. There is no theme to my knowledge that displays titles and descriptions on the thumbnail overview pages. The title and description is display on the single image page normally. The site you referenced uses a custom theme not available for general use.

You would have to modify an existing theme or even better create your own custom theme to fit all needs: https://www.zenphoto.org/news/theming-tutorial/

2. Sorry, no ready made solution for this exists. It would have to be coded.

I guess my request is slightly unusual, as I'm looking for something more than just a photo gallery theme, but rather an online platform to display historical photographs, with Titles and Descriptions showing with the thumbnails, and upon which visitors can comment.
Any online museum would probably want something similar to display its artefacts online. The descriptions are important because it's not always clear from the thumbnail photo just what it is.
I've been having another look at Vincent Bourganel's zpbootstrap theme that, in terms of layout, is close to what I'm looking for (particularly the album-normal-size view). It's just lacking the display of Title and Description under each thumbnail and, preferably, a couple of buttons so visitors could navigate back to my main website.
I know it can be done, because the Rail Geelong site does it, and I only wish I had the skills to develop such a custom theme, or the money to pay someone to do it for me.

Well, Zenphoto is more than just a photo gallery in any case. Just look at our own site ;-)

The request is not per se unusal, there is just not a theme that may fullfill everything you like to have. And yes, there are too few ready made themes but someone had to create and maintain them afterall. That's why you can create your own theme or modify an existing.

I am not familiar enough in detail with zpbootstrap by @vincent3569. I it implements the normal breadcrumb functionality which optionally can link to a parent site if the related options are set.

Just to close out this discussion, I can confirm that zpbootstrap does display the image title below each thumbnail, and the title and description below the full-size image.