Feature Request: Button to toggle all displayed locations

When you view the map in an area that is highly packed with items/images/WP articles/etc (eg. a city) it’s very hard to see where you are on the map.

My suggestion is to have one button to toggle all entries on and off so that it’s easier to navigate on the map.

This would also be highly welcome on mobile devices since it’s almost impossible to use this tool on eg. a smartphone.