Arnarker is a cave that is the entrance to a lava tunnel in the Leitarhraun lava field, north of Road 380, near Thorlakshofn (Þorlákshöfn) in southwest Iceland.
The Arnarker can still be viewed – there is a short path leading to it from the parking lot on Road 380 – but the ladder that once allowed visitors to descend inside the tunnel has been removed and the Arnarker itself has a “permanently closed” status. It can only be viewed from above.
Since the cave from above, from the surface, is not very impressive, and the 380 road that you will get here is in poor condition, the whole thing is unlikely to be recommended. In the area you will find several other lava tunnels available to visit (with a guide and for a fee, such as Raufarhólshellir on road 39), and in other parts of Iceland you will find similar places, also available for free (such as Surtshellir in the Kalmanstunga area). Certainly the largest and most famous lava tunnel caves are – accessible only with a guide – the Vidgelmir and Vatnshellir.
Those wishing to reach Arnarker from Reykjavik nonetheless should take Road 1 east and turn south onto Road 39, then southeast onto Road 380.
There is a parking lot or staging area on Road 380 in the right place, from which one should head northwest, still on a clearly visible path (as long as it is not covered with snow). After about 10 minutes you will reach the cave.
