Tal Abyad, Syria (CNN) ISIS has been forced from one of its stronghold outposts, a key access point to its self-declared capital, where it was entrenched for two years. And the defeat along a vital stretch of terrain could be a potential blueprint for more military successes against the militants.

In freshly-liberated Tal Abyad -- not far from the Syria-Turkey border -- the scars of battle are everywhere, as are ISIS booby traps.

ISIS ruled this rural landscape with impunity, fortifying it to defend a vital frontier and a key access point to their capital.

The YPG, the Kurdish fighting force, had tried and failed to capture key towns in the past. ISIS would counter each assault with heavy weapons, car bombs and suicide bombers, each time forcing the YPG to retreat.

But in the past month, the battlefield dynamics have changed.

U.S.-led coalition airstrikes pounded ISIS fighting positions, taking out the terrorist group's armored vehicles, heavy weapons, headquarters, and other targets, allowing the YPG to barrel through around 80 kilometers (50 miles) of ISIS territory to reach the major prize -- Tal Abyad. The town is the gateway to a crucial border crossing with Turkey.

Key position

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The combination of coalition power in the air and a committed force on the ground was so effective that ISIS fighters rapidly retreated.

ISIS blew up a bridge, and put up a fierce, but brief, fight -- and then drew back.

The Kurdish force had estimated it would take them weeks to defeat ISIS in Tal Abyad. In the end, it happened in two days.

YPG leaders on the ground tell us that the effectiveness of the assault was thanks to direct coordination between the coalition and their upper command.

"When the coalition against ISIS was formed, we were the only force that was committed in the fight against ISIS," said Bilal Rojava, the YPG commander overseeing the Tal Abyad front. "The coalition forces saw this and coordinated with us."

That coordination began during the battle for Kobani last fall, and has developed since.

Now, the drive to Tal Abyad is scattered with the carcasses of ISIS armored vehicles and the remains of its defensive positions.

Buildings once occupied by ISIS, the walls still etched with crude renditions of its feared flag and Quranic inscriptions, lie abandoned.

Cross-hair targets spray-painted on the walls of a former ISIS base are peppered with bullet holes.

Huge dirt berms that blocked the road have been cleared to allow vehicles to pass.

There are underground tunnels, so that ISIS fighters could move undetected, around one village we are taken through. The tunnels -- clearly dug out by heavy machines -- are about a meter (3.2 feet) wide and high enough to easily stand in. Metal sheets form the roof, covered in a thick layer of dirt, are hard to detect with the naked eye. But they are not thick enough to fool the thermal cameras the coalition has at its disposal.

Well-equipped force

Inside Tal Abyad, ISIS' seemingly endless supply of armaments is evident. In the back of a mosque named for former al Qaeda leader Osama bin Laden, the YPG is clearing out an ISIS bomb-making factory.

The flatbed of a truck is half-filled with artillery rounds waiting to be hauled off. There are large artillery rounds, detonation caps, and plastic bags of white sticky powder -- a low-grade explosive. A tailor-turned-YPG weapons specialist tells us the white powder is a key element in ISIS's notorious and unending suicide bombs.

The YPG is still clearing out towns and villages from booby-traps and mines. In one village, we hear an explosion in the distance. The local commander takes off to determine the cause, returning to tell us that they were from explosives ISIS left behind.

Booby traps

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In Tal Abyad, a building is off limits. ISIS is known to booby trap buildings, and the YPG commander tells us not to touch the door.

Through the closed gate and hazy windows one can barely see into the guard house, but stacked against its back wall are makeshift bombs with strands of detonation cord snaking out of them.

Throughout the ruined town and surrounding countryside, there is evidence of how well armed ISIS is. Its arsenal has been massively enhanced by battlefield gains that began in Mosul and spanned over huge swaths of Iraq.

Even the committed YPG had been struggling to beat ISIS's defenses -- until the airstrikes began.

"If the coalition strikes, and there is no force on the ground, there would be no real impact on ISIS. And if we advanced without coalition strikes, we would not have advanced this fast," Bilal said.

This is perhaps the formula the U.S. wants to implement. Backed by coalition airstrikes, an effective and reliable partner on the ground can succeed in defeating ISIS.

But the battlefield is vast, and in this complex region with competing interests, a blueprint for success is hardly easy to replicate.