Getting Precise Geo-Coordinates, When No Map Has It

An example of the communication going on in chat channels between people volunteers on the 4636 project (there is nothing as valuable as local knowledge):

(12:52:55) (Dalila): I need Thomassin Apo please (12:53:02) (Apo): wait (12:54:53) (Apo): Kenscoff Route: Lat: 18.495746829274168, Long:-72.31849193572998 (12:57:25) (Apo): This Area after Petion-Ville and Pelerin 5 is not on Google Map. We have no streets name (12:58:05) (Dalila): @Apo I thank you for ur help (12:58:24) (Apo): you are welcome (12:58:53) (Apo): I know this place like my pocket (12:59:08) (Dalila): :) (12:59:14) (Dalila): thank God u was here