The Bills’ Rocks are desolated rocks offshore nine miles from Achill Island designated as a Special Protection Area. They stand one hundred and twenty-four feet above sea level.

There is an old legend that recognised these rocks as the remnant of the lost Atlantis, a disappeared mythical continent whose end the Greek writer Plato, who lived four hundred years before Christ, wrote:

"At that time the Atlantic ocean was navigable and there was an island greater than Libya and Asia together. On this island a very rich war-race lived; but huge earthquakes and deluges took place and brought with them desolation in the space of one night, so all these people were merged under the earth, and Atlantis Island itself being absorbed in the sea entirely disappeared."

The Bills’ Rocks were called after the Danish Captain Mathias De Bille.

On 14th December 1781, the Royal Danish Navy frigate Bornholm left Copenhagen bound for the Danish West Indies. Its captain was Mathias De Bille. On 17th January 1782 as the frigate reached the Northern Coast of Ireland, a violent hurricane rose and drove the ship south towards Clew Bay.

The frigate lost its foremast and bowsprit; nevertheless, the captain was able to steer the ship into Melcombe Bay near Newport and avoid the vessel to be smashed against the Bills’ Rocks.

Several sailors of his crew were lost at sea and several were struck down with an incurable fever. The sickly men were hospitalised in a building at Mellow's Point on Melcombe Bay. Unfortunately many died and were buried in the graveyard beside this temporary hospital.

The captain himself caught the fever and the local merchant John McLoughlin looked after him. Mathias De Bille died in John’s home on Newport's Main Street on St. Patrick's Day, 1782. He was buried with military honours in the old parish churchyard in Newport and Colonel Sir Neale O'Donnell led a parade of Volunteers at the funeral.

In honour of Mathias De Bille, the Danish Royal Family funded the construction of the landmark De Bille House on Newport's Main Street.