Secrets of Pans Rock Bridge and the Mysterious Devils Churn Caves on Ballycastle Beach Co Antrim

Recently we enjoyed having a wee break at Ballycastle on the windy and rugged north Antrim Causeway coast.
One of the days we went for a walk along Ballycastle's scenic but largely deserted beach. It's a shame but the beach like others in Northern Ireland is usually too windswept and cold to sit out on and the water is equally too cold to swim in.
So we walked the mile long beach and did a bit of exploring-
This beach walk offers terrific panoramic views back over Ballycastle, its beach, and out to Fairhead and 6 miles distant, Rathlin Island.

At the far end of Ballycastle beach we discovered the Pans Rock Bridge and alongside it, what is locally known as, the Devil's Churn. As we are from Belfast we had little idea of the stories or dates, behind this strangely named bridge and the mysterious Devil's Churn.

Some of the locals we spoke to believed that salt panning occured here at the end of the 18th century. The original rock bridge was built to facilitate this salt extraction. Others added that years later, Pan's Rock used to be popular for bathing and diving. In fact the remains of the irons, which held the diving boards in place, can still be seen at low tide.

Back home and a quick trawl of the internet revealed some interesting answers.
The Devi's Churn lies at the bottom of steps going down into a 'drowned', cave. 'The Devil's Churn is the area of great turbulence at the bottom of the stairs cut into the rock. The churning is caused by an underwater tunnel in the rock/seabed running out to sea. If you go when the water is at just the right level, it acts like a blowhole, which is out of synch with the arriving waves, sucking away dramatically, only to blow water high into the air seconds later.
I couldn't find any information to explain why those steps led down into that tunnel. What were they for? Anyone.

I'm also told that there are nearby faces carved into the rocky islands. I'm afraid we didn't know about them so we didn't even try to look.