Dimmuborgir, the lava city and its church arch

Dimmuborgir means dark castles, and the name is fair: a square kilometre of black lava standing in pillars, spires, arches and hollow shells, left when a lava lake drained away and its crust stayed put. Marked trails of different lengths loop through it, and the shortest of them reaches Kirkjan — the church — a tall arched cavity you can walk into and out the far side.

Inside the formations the photography is all about frames within frames. Put the couple in Kirkjan's arch and shoot from outside so the black vault surrounds them and the lit landscape shows through; step in and shoot out and you get the reverse, a silhouette against green. Along the trails there are constant natural windows and pillars to shoot around. Because the rock is black and the sky is bright, this is a place where a photographer will use flash or shoot for silhouettes; overcast light narrows the gap and makes everything easier.

The rock keeps the trails in shadow much of the day, so the light on faces is soft and hours matter less than usual. In summer the sun stays high and late — an evening session gets warm light on the tops of the pillars with the paths already cool. In winter, snow on the black towers is the version that photographs best, though only a few hours are usable and the trails can be icy.

Practical: the shortest loop takes twenty to thirty minutes on packed gravel with some uneven steps; the longer loops involve real walking. Flat shoes, and gravel dust on hems is normal. Stay on the marked routes — the lava is sharp, the ground between formations is fragile and easy to get lost in, and this is a protected area where straying damages the moss and the crust. Check current rules before flying a drone, and expect midges here in warm, still weather from late spring.