The island of Achill sits just off of Ireland’s northwest coast, connected to the mainland by a bridge. The island features rocky cliffs and some beaches with glorious views of the Atlantic in addition to rolling green hills.

In the 1980s the island lost one of its beaches to storms, which left only rocks along that part of the coast. Then in 2014, storms again brought destruction to Dooagh. Paths to the waterfront and a pier were washed out as a result. The video below shows the rock-covered shoreline left after the sand washed away.

But around Easter this year, the beach reappeared, the Guardian reported. Sean Molloy of Achill Tourism told the Guardian that cold winds came in from the north during that time which may have contributed to the reappearance of the beach.

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While it is fairly common for beaches to erode, it’s rare if not unheard of for them to reappear quickly. Beach erosion occurs when sand is removed from the beach by currents and waves. Waves and currents are stronger during storms and frequently are accompanied by wind as well. They can pull sand from shore and transport is out to sea, sometimes creating sand bars.

While it’s normal for beaches to regain sand, the situation in Dooagh is unprecedented.

“What’s surprising about this is how rapidly it came back,” Bob Guza, professor of Oceanography at the Scripps Institute at the University of California San Diego, told the International Business Times. “Usually the recovery is gradual, the sand usually comes creeping back over time,” he said.

"This may or may not be the same sand that came back."

Researchers know very little about offshore sand and how it moves around, he explained, in part because the sand is so thick and it moves so frequently and easily. He said whatever happened in Dooagh indicates something unique about that specific location and the way the circulation of sand and water happens there.

For residents in Dooagh, the new beach is exciting. Molloy told the IBT in an email many tourists had already come to see the newly reappeared beach. Achill has a number of seaside towns that draw tourists throughout the year.

“But the Village of Dooagh, where this beach is situated, has lost three hotels, [and] several restaurants and shops since the beach went. Maybe if the beach stays — some of these will reopen?” Molloy said.

But Guza cautioned while the beach is back, it may not be there for long.

“In that part of the world there’s a lot of rocky shoreline. The sand isn’t all over the place; it's patchy,” Guza said. “And it’s not thick either. The rocks and cobbles on that beach are still there, there’s a layer of sand above those rocks and cobbles, and it can go away just as quickly as it appeared.”