Fence is monitored 24/7 by armed guards stationed at strategic points

Country's authorities want to block people smugglers coming via Bulgaria

Keep out: Police chief Ivan Stoyanov at the fence

Stretching far into the horizon, this is the super-fence blocking thousands of migrants hoping for a new life in Europe.

As police in Calais struggle to contain thousands trying to storm the Eurotunnel in their desperation to get into Britain, the Bulgarian authorities are shoring up their border with Turkey.

The barriers around the ferry and Eurotunnel terminals in Northern France are breached night after night by migrants trying to reach the UK.

By contrast, the new section of fence being constructed to seal Bulgaria's entire border is designed to appear all but impregnable,

The local authorities are hoping to put off the ruthless criminal gangs exploiting families fleeing war and terror in Syria, Iraq and North Africa from trying to enter Europe via Bulgaria.

Bulgarian Border Police chief Ivan Stoyanov said: 'Our operation has stopped more than 500 migrants from crossing in the last month alone.

'Half were arrested by our Turkish colleagues and half were sent back. The aim of the migrants is not Bulgaria. They often want to get to other European countries like Britain. They use us as a place of transit.'

Infra-red motion-sensitive cameras mean parents carrying their children in bundles are rounded up as they try to smuggle themselves across Europe's eastern frontier under cover of darkness.

The fence is monitored 24/7 by armed guards stationed at strategic points along its current 50-mile length.

Border police look into Turkey from watchtowers with binoculars.

Bulgaria is also drafting in soldiers to fortify its defences against the ISIS terror group as fanatics try to slip back into Europe.

The country was previously considered an easy route back and ISIS included Bulgaria in its declaration map of an Islamic caliphate.

Imran Khawaja, who was pictured posing with a severed head in an ISIS stronghold, travelled from Bulgaria in his cousin's taxi after making the crossing last year.

And French terror suspect Fritz-Joly Joachin - linked to the Charlie Hebdo gunmen Cherif and Said Kouachi - was also arrested in Bulgaria near the border crossing.

The fence is monitored 24/7 by armed guards stationed at strategic points along its current 50-mile length

But for thousands of terrified families fleeing the extremists, the fence also represents the end of a desperate dream.

At the border police station in Elhovo, Bulgaria, seven officers monitor a bank of TV screens displaying live footage along the fence.

They are in constant radio contact with their colleagues on patrol.

Boris Chershikov, UNHCR spokesman in Bulgaria, explains many arrivals have had their ID documents taken from them by smugglers as a ransom.

'We are seeing a lot of people fleeing ISIS,' he confirms. 'It is unprecedented with so many conflicts simultaneously happening, leading so many people to flee.