All the pins on the Places map now have a unique id, called a 'Marker Id' to enable unique identification of a pin. This also means that each pin has a unique URL. 

To get this URL, open your places activity in preview mode. 

Just click on the pin of your choice, to bring it into focus, and copy the URL from the top which has the unique ID of the pin.

In the example above, the shareable URL is - https://demonstration.engagementhq.com/places/maps/Park#marker-7572.
When a user clicks on the URL, the map will open with marker id pin 7572 in focus.

NOTE - Both, the administrators and the participants can copy the URL from the browser window.