You can use the WP Geo widget to display a map in your sidebar. This will display markers for all currently visible posts. If you are on a post page it will display one marker and if you are viewing a category or archive page it will display a marker for each post on that page with location information.
In the WP Geo settings you can set a default map zoom. The widget will always zoom out so that you can view all the markers it is displaying, but if it is only showing 1 marker or a couple of markers close together, it will never zoom in further than the Default Map Zoom you set in the settings.
By default, the widget will use the polyline settings you have set in the main WP Geo settings. Here you can trun polylines on or off and set the colour of polylines.
When adding a widget, you can override show of the default settings and customise the look of the widget.
You can add a map title which will appear above the widget.
You can set the dimensions of the widget. I suggest for most themes you will want to set the width to 100% so the map stretches to the same width as your sidebar. However, you may find that with some themes this does not appear as expected and you may need to set an exact width.
By default, the widget will display the same type of map as you have set in your main WP Geo settings. You can override this by selecting a different map type in the widget’s menu. You can also choose to override the default polyline setting.