On this page, we'd like to let the user know that the big captions over the images can be clicked. (We don't have any links right now.) The pages that open will be on the same server, so the "External Link" icon from Fontawesome won't work. We'd like it to be unobtrusive yet easy to notice, if that were possible! Not all captions will be clickable; just some.
We thought about underlining the items, but that's too ugly in this case. What UX elements would make this obvious both for mobile and desktop users?
UPDATE: Here is the carousel on a mobile device:
And here it is on the desktop: