One of my favourite features of Mavericks is the new Maps app, specifically the ability to share a location or directions direct to your iOS device, as long as it’s running iOS 7.
The way it works is, is that you find the location or directions you want to share in Maps, and then from the Share button/menu select any iOS device attached to the same Apple ID.
The map should then appear in the notification centre on your iOS device, which, when read will take you to the iOS maps app.
A lot of people, including myself, have found that none of my iOS 7 devices are appearing in the share menu after upgrading to Mavericks.
There is an easy fix however. On Mavericks just go to the iCloud preference pane and logout, then log back in again and all should be well.
Seems to be a small glitch during the setup of Mavericks.