Short story
We need a control to convey the idea of going back to the initial position of the map - the fixed zoom and position as it is saved in wikitext.

Long story
Maps are interactive. An editor initially configures a zoom, longitude and latitude for the center of the maps.
Once loaded, the user can play with the map: move the center of the map away from its initial position, zoom in or zoom out.
Since T135556, a user can also share a full screen map, at the zoom level and position he is currently looking at (different from the initial position configured by the map "creator/editor").

Without a dedicated control, a user has to reload the webpage in order to go back to the initial position.
We want to provide an easy way for the user to retrieve the initial position without reloading the entire webpage. The action itself can be done very easily with JS, the only question is where on the UI, and on what element, should the user click to trigger the action.

Requirements

• The control/action will be displayed only when the current position/zoom differs from the initial one.

Questions

• Should we have a label displaying on top of the map such as: "Back to initial position" OR have an icon that can convey the idea without a text?
  • Done. Per comments, the undo icon seems to work :
    
• Which position? (please stick to top/topleft/left/bottomleft/bottom/bottomright/right/topright)
  • see comments
  • see T136982 (Define guidelines for positioning map controls)