F-roads are highland tracks. Many ford rivers. They are closed in winter and into spring. Opening dates move with snowmelt. The road agency publishes them. A 2WD car is not an F-road car. Rental contracts usually say so. That is a plate and insurance fact, not a sales pitch, and we are not here to put you in a larger vehicle.
Landmannalaugar
The named camp in the rhyolite of the southern highlands. You reach it on F208 or F225 when those roads are open. The rivers change depth in an afternoon. A ford you crossed at ten can be a different river at four.
Self-drive caution
Highland driving is a different skill from Route 1. If you cannot read a ford, do not enter it. There is no prize. Recovery is slow and expensive in a way this gazette will not quote, because the point is not to shop it. The point is to stay out of the water if you do not know it.
Closed gates mean closed. Walking around a barrier to put a car on snow is how tracks get torn and people get stuck. Wait for the opening, or walk where walking is allowed.
The interior is not a shortcut. It is a summer network with its own weather. Route 1 will still be there when the F-roads are mud.