Plenty of trails criss-cross the region, but only a few of these are marked or visible on the ground. In particular, this is the starting or ending, depending on your direction of travel point of Laugavegurinn, the Landmannalaugar - Þórsmörk trail - a demanding 2-4 day hike with huts and campsites on route. It can also be extended by 1-2 days by continuing to Skógar.
Laugavegurinn is by far the most famous and most walked hiking trail in the country, regularly listed as one of the top hiking trails on the planet. As a result, demand for use of the huts is high, and in high season they should be booked many months in advance. The alternative is to camp, which is not subject to reservation. You should bring food with you since, aside from a small and very expensive shop present at Landmannalaugar during high season, there is no opportunity to buy food on the route, neither at the huts nor at Þórsmörk. You should also be prepared for unpleasant weather - low temperatures, high winds, heavy rain, occasionally some snow, even in summer.
Laugavegurinn is regularly marked with clearly visible marker sticks every 200m or so. Further, during high season end June to late August, it is heavily walked, so there is little risk of getting lost. In the early part of the high season, some parts of the trail are likely still to have snow cover, which may make navigation more difficult, and presents risks of falling through snow bridges.
Outside high season, the amount of snow cover is increased, and the number of walkers greatly reduced. This increases the difficulty of navigation, and also the risk that you will not be discovered if you get into difficulties. There is no GSM coverage in the area. A small number of off-season hikers have died of hypothermia as a result of such incidents. Off-season hikers should also take account of the period during which there is road access to Landmannalaugar.
Horseback riding is also available, for shorter or longer rides. The horse riding trips visit places which can often be difficult to access on foot and are not accessible by car as there are no official roads, as an example into Jökulgil Glacier Valley. No reservations are needed. The horse rental is open from 1st July.