Geolocation - want pins to show multiple items

Hello,
I added Geolocation data to the items on my site http://insurancearchive.org/geolocation/map/browse. Although many items on the map have the same location, when I click on a pin, it only shows 1 of those items. Is there a way to make it show all the items with that pin?
Thank you.

That sounds like all the pins for different items are being drawn on top of each other, because they all have the same location. The result is that they all look like a single pin.

If there's a little variation in the locations, when you zoom in they'll probably appear as different pins.

The system goes by 1 pin-1 item, so without variation in location, they'll all still be drawn on top of each other.