idea: a combination of PHP and Leaflet.js
in config file e.g displaymap = "true"
on top in menue section there is a map zoomable displayed
e.g 100% width 20% height
PHP extracts geotag data from the images in a folder and serves it as JSON.
Leaflet.js renders the map and places markers at the photo locations.
option1: Clicking a marker displays a popup with the photo thumbnail or
option2: Leaflet.js places very tiny thumbnails on the map. clicking on a thumbnail opens the foto in a popup.