Arnarker is a cave that serves as the entrance to a lava tunnel on the Leitarhraun lava field, north of Route 380, near Thorlakshofn (Þorlákshöfn) in southwestern Iceland.
Arnarker was once closed to visitors, but it is now open again (free of charge!). A short path leads to it from the parking lot on Route 380, and a renovated spiral staircase takes you to the bottom of the sinkhole.
The total length of the corridors accessed through Arnarker is over 500 m – approx. 100 m to the south and as much as 400 m to the north. If you decide to explore the cave, remember that it is protected and must not be damaged or littered.
inside the northern tunnel (Arnarker)
There are several other lava tunnels in the area that are open to visitors (with a guide and for a fee, e.g. Raufarhólshellir on road 39), and in other parts of Iceland there are similar places, also accessible for free (e.g., Surtshellir in the Kalmanstunga area).
Certainly the largest and most famous caves in lava tunnels are – accessible only with a guide – the caves Vidgelmir and Vatnshellir. Admission to these caves is not expensive, and you can actually go quite deep, safely and comfortably, into truly huge and beautiful lava tunnels.
Those who still want to get to Arnarker from Reykjavik should take Route 1 east and turn south onto Route 39, then southeast onto Route 380.
On Route 380, there is a parking lot or parking space at the right place, from which you should head northwest, still following a clearly visible path (unless it is covered with snow). After about 10 minutes, you will reach the cave.
Old photos, from when the spiral staircase was not there:
