"Favourite star" icon? Sorry but stars have been used as landmarks since forever.

To be fair, it's not terribly common, especially to use a gold colored star. Usually a black star or a white star with a black outline is more common.

However you're right, it's not without precedent. Here's a very similar star being used by the US Government in one of their maps: http://www.usgs.gov/state/images/maps/AK.jpg

I read the comments first and I assumed you may be exaggerating a bit. Certainly it's fine to use a "*" on the map to distinguish from cities?

It could only be worse if they had chosen a smiley emoticon.