Instagram is phasing out its photo maps feature. This feature allowed you to see yours and others' geotagged photos on a map, with all photos taken at a particular location appear bunched together and as you zoom into the map the images would place themselves accordingly to different locations. The ability to see others' photo maps has already been removed but you can still see yours for now, but that should change shortly. According to Instagram, not enough users were using this feature. If you have no idea that this feature existed or that it disappeared from everybody else's...
Source: http://www.gsmarena.com/instagram_drops_photo_maps_feature-news-20372.php