Fascinating terrain and good beer – an appealing combo for many a traveling geologist, or so I’m told. As luck, or perhaps leprechauns, would have it, the island nation of Ireland is known for both.
Geologists believe the home of Guiness and Gaelic was formed nearly 470 million years ago when two different continents collided. According to the Geological Survey of Ireland, “The land that is now Ireland then moved north close to the equator. At this time, known as the Carboniferous period, a sea extended across Ireland allowing for the formation of sedimentary rocks such as sandstone and mudstone. Over the next 50 million years, limestone deposits formed in the warm waters.”
Visitors can see evidence of this collision in the direction and formation of the island’s mountains: The range displays long axes that trend northeast to southwest, creating a sort of scar where the crash occurred.
But you need not climb these peaks to immerse yourself in geological wonder while visiting Ireland. Let’s look at two spots that should be must-visits during the day, when you’re not holed up cozy in a traditional pub with a good Irish beer or whiskey (see sidebar).
The Blarney Stone
This legendary Irish site is a wall within the Blarney Castle in Cork, which was constructed in 1446. The story has it that those who kiss the stone will be gifted with eloquence and persuasiveness, so when you visit, make sure to give it a peck!
The geology of the Blarney Stone was largely speculative until roughly 2014, when an intern at the Hunterian Museum in Glasgow, Scotland, found a microscopic slide of the stone among the institution’s nearly 40,000 geological microscopic slides. Findings suggest the stone is a roughly 330-million-year-old Carboniferous limestone.
The University of Glasgow reported, “Analysis indicates the Blarney Stone is a limestone, made of the mineral calcite, and containing recrystallized and slightly deformed fragments of fossil brachiopod shells and bryozoans.”
How to visit: Cork is a three- or four-hour drive from Dublin, or you can reach it via bus or train. It is recommended to budget at least three hours to visit Blarney Castle, so those driving from the nation’s capital on a day trip may wish to hit the road early.
Climb the 125 steps to near the Blarney Stone, then you must grab hold of an iron rail and lean back to give it a kiss (staff will help ensure you don’t fall). Be prepared to potentially wait in a long line for your turn. Once you’ve been bestowed the “gift of gab” from the stone, there is still plenty to see at the castle. Wander through the maze of dungeons and make sure to visit the Poison Garden, which contains some of the world’s deadliest plants.
Giant’s Causeway
If you plan to cross into Northern Ireland and/or visit Belfast, a trip to Giant’s Causeway is essential. Giant’s Causeway is a promontory of roughly 40,000 basalt columns along the island’s northern coast. Each pillar has between five and seven sides. They range from 15 to 20 inches in diameter and up to 82 feet in height.
On the site’s geology, the Encyclopedia Britannica reads: “Formed 50 to 60 million years ago, during the Paleogene Period, the Giant’s Causeway resulted from successive flows of lava inching toward the coast and cooling when they contacted the sea. Layers of basalt formed columns, and the pressure between these columns sculpted them into polygonal shapes.”
How to visit: There are tons of great group tour options leaving Dublin each day. You can also drive or cycle to the Giant’s Causeway, a UNESCO World Heritage site.
Spend ample time walking up and down the basalt pillars, then peel off to enjoy the nearby trail network. Many of the top trails are under two miles round-trip, or there is a guided five-mile hike of the area’s nearby cliffs for those with a bit more stamina. Several of these trails pass by Hamilton’s Seat, a high point of the area, literally and figuratively.