The war that never ends between the Koreas

On a clear day, residents on Yeonpyeong Island can see North Korea, only 10 kilometres away.

This South Korean border island is one of five, along the maritime frontier marking the two countries.

But the frontier is not recognised by North Korea, in fact it's not recognised internationally either.

That makes tensions especially high for the people living here.

On the beaches rows of anti-landing spikes and barbed wire fences frame the coast.

While long-range cruise missiles, capable of striking the North Korean capital of Pyongyang sit on the cliff-tops.

(SOUNDBITE) (Korean) HEAD OF YEONPYEONG ISLAND RESIDENTS' ASSOCIATION CHOI SUNG-IL SAYING:

"When I was little, the sound of artillery was like a lullaby to me. But since the 2010 bombing, every time I hear the sounds of gunfire or artillery during military exercises, I start to feel jittery."

North Korea warships and fishing boats routinely sail over the line, which has led to a spate of