Welcome to the Valley of Thor, a legendary oasis of lush greenery nestled between three mighty glaciers. Getting here is an adventure in itself, as you'll need a special mountain bus or super jeep to ford the wild, unbridged rivers that guard this paradise. Once you arrive, you'll find a network of trails for every level, from the popular 3-4 hour 'Thórsmörk Highlights' loop through birch forests to the challenging all-day Tindfjöll Circle with its breathtaking panoramas. It's a raw, powerful landscape that feels like stepping into another world.

There are lots of shuttles available in high season that leave from the Selfoss area and the town of Hvolsvöllur

Do not try and drive here you need a super jeep the rive crossings are no joke.

this blog has some great info on Thorsmork and the surrounding area https://epiciceland.net/detailed-guide-thorsmork-iceland/