The area in Co Wicklow, which has been in use for more than a century, is strewn with unexploded shells and other ordnance.
The drama began when gardai asked the Dublin & Wicklow Mountain Rescue Team and the Glen of Imaal Irish Red Cross Mountain Rescue Team for help yesterday afternoon.
The three men and two women, all experienced walkers, had set off from Glenmalure Youth Hostel. In fading light, they became disorientated and descended towards the Glen of Imaal.
When they realised they were lost, they contacted mountain rescue.
They were located using their smart phone. Soldiers were sent from the Army Warden Range at Seskin School on all-terrain vehicles and liaised with mountain rescue to get to the walkers, who were all unharmed.