If you look at a local event you are given the option to precisely place a map pin (which mumsnet has placed by postcode) If you follow the link it takes you to the google map with the pin.
However, by default the map is very zoomed out (too far to accurately place a pin), and if you zoom in the pin vanishes, making the whole exercise impossible and pointless 
Can the pin be made to be visible at all zoom levels, not just the default?