Another useful utility for leaders wanting to mark features on a map and then display them on this website is called Pin In The Map.
With this you can display an image like this:-
I added this image by using the Apple Mac programme Skitch, clicking on the image takes you to the map on PinInTheMap.
Nearby is still the better utility for finding postcodes very useful for folks with TomTom etc. However, PinInTheMap, is more precise for obscure car parks.