.JPG?width=1800)
Geology
Strange Geological Wonders
The Giant's Causeway in County Antrim, Northern Ireland is 40,000 basalt columns, mostly hexagonal, formed when a fissure eruption 60 million years ago cooled exactly evenly. Local Irish legend ascribes them to the giant Fionn mac Cumhaill, who supposedly built a causeway to fight the Scottish giant Benandonner. The science is more boring and more astonishing: when basalt cools uniformly from one direction, it cracks into a hexagonal close-pack pattern, the same shape as a beehive cell, because that's the most efficient way to dissipate stress.
These seven geological wonders are formed by ordinary processes (cooling, dissolution, freezing) operating at unusual scales. Each one shows what happens when chemistry is given enough time and enough space.
Below: the season, the angle that photographs it best, and the one local geologist worth booking.
.jpg?width=1400)
Late afternoon light, looking east. Photo by our regional correspondent.
Why This Place Matters
Giant's Causeway, Northern Ireland — 40,000 basalt columns from a single 60 Ma eruption.
Erta Ale, Ethiopia (Danakil) — one of only six permanent lava lakes on Earth; the molten lake has been continuously visible since 1906.
Pamukkale, Turkey — calcium-rich hot springs depositing travertine terraces at 1 mm per year; visible from the air as a white scar in the Anatolian plateau.
A Short History
The Wave (Coyote Buttes, Arizona) — Navajo sandstone deposited as cross-bedded dunes 190 Ma ago, then uplifted and weathered into 'currents'. The US Bureau of Land Management issues only 64 daily permits — 16 by lottery, 48 by advance application.
Eisriesenwelt (Werfen, Austria) — the world's largest ice cave, 42 km long; cold winter air sinks into the cave and freezes melt water into formations that persist year-round.
Cano Cristales, Colombia — the 'river of five colors' in Serranía de la Macarena; the red comes from Macarenia clavigera, an aquatic plant that blooms only July to November when the water is at exactly the right level.
What You Will Actually See
Giant's Causeway, Northern Ireland — the Grand Causeway and the Organ rock formation; visit at low tide to walk on the hexagons.
Erta Ale, Ethiopia — the only way is a 4-day jeep convoy from Mekelle with an armed escort; you sleep on the volcano rim and watch the lava lake at night.
Pamukkale, Turkey — visit at dawn before crowds; walk barefoot up the travertine pools (mandatory) and combine with Hierapolis Roman ruins above.
The Wave, Arizona — 5.5-mile round-trip hike from Wire Pass Trailhead; permit lottery on recreation.gov.
Eisriesenwelt, Austria — 1.5-hour guided tour (German with English explanations); bring a heavy jacket — internal temperature −1°C even in August.
Cano Cristales, Colombia — fly La Macarena from Bogotá or Villavicencio, July–November only.
Vinicunca (Rainbow Mountain), Peru — 5,200 m, day trip from Cusco; altitude affects roughly half of visitors.
Sailing Stones at Racetrack Playa, Death Valley — 3-hour drive on dirt road from Furnace Creek; the stones leave tracks across the dry lake bed.
The kind of detail you only notice on the second visit.
Interesting Facts
A few quick notes on strange geological wonders before the section below.
These are the details our correspondents most often get asked about by readers planning a trip.
Practical Information
Giant's Causeway — National Trust visitor centre opens 9 am; cash for the optional audioguide. The hexagons are slippery when wet.
Erta Ale — only with ETT, Wild Frontiers, or Origins Ethiopia (armed escort mandatory). Best November to March.
Pamukkale — open 6:30 am — 19:30; arrive at opening to avoid Antalya day-trippers. €18 includes Hierapolis.
The Wave — apply via recreation.gov 4 months ahead. The hike has no marked trail; download the BLM map.
Interesting Facts
- The Giant's Causeway contains approximately 40,000 basalt columns, most hexagonal, formed 60 million years ago during the Paleocene Thulean volcanic episode.
- Erta Ale's lava lake has been continuously molten since at least 1906, the longest documented permanent lava lake on Earth.
- Pamukkale means 'cotton castle' in Turkish; the travertine terraces grow at approximately 1 mm per year and have been forming for around 14,000 years.
- The Wave at Coyote Buttes North limits visitors to 64 per day to preserve the soft Navajo sandstone, which can be eroded by foot traffic.
- Cano Cristales's red colour comes from Macarenia clavigera, an aquatic plant endemic to the Serranía de la Macarena and visible only July–November.
Most travellers walk straight past this corner. Stop and look up.
How To Visit
Belfast → Causeway: 90 min by Translink Goldliner 221X, £15 return.
Addis Ababa → Mekelle: 1h30 flight on Ethiopian Airlines.
Istanbul → Denizli (Pamukkale): 1h flight on Turkish Airlines + 30-min minibus.
Cusco → Vinicunca: 5 am pickup, 3.5h drive + 5 km uphill walk.
Final Thoughts
Geological wonders make landscape feel deeply old. Spend at least an hour. Walk in silence for a stretch.
Of the seven: the Giant's Causeway is the easiest. Erta Ale is the most dangerous and the most rewarding. Pamukkale is the most over-photographed and still worth a visit.
Take a geologist's guide if you can. The local geologist in Pamukkale (Yıldız Uçansu) explains the chemistry on the spot and changes how you see it.
If you read this article and noticed something we got wrong, please write to us. Reader corrections shape what we publish next.
Ada Petrović
Regional correspondent for WIGO Trips. Writes about overlooked places and quiet histories.
