Each of the watchtowers that line the roads of the Guarded Land is provided with a heliograph. This is a complex device which is used to turn the rays of the sun so as to send messages to neighbouring towers. Operated by the ammonites who staff each tower, messages can thus be jumped from one tower to the next back and forth between the Wise and the furthest parts of the Guarded Land.

Heliography is very fast: a journey from Nothnarlan to the City at the Gates would take a traveller along the road more than forty days and yet a message can be transmitted by heliograph from Nothnaralan to the Wise in the heart of Osrakum in around one third of a day.