On the map, you'll see at least one marker that represents a gym location.  If you hover your mouse pointer over the marker, the name of the location will appear.  If you click on the marker, a box will pop up with some information and a tab to click for driving directions.  I think you can do the rest.

If there are any locations that are missing, please let me know.  Just send the address of the missing location to the webmaster .