I recently visited Rauðfeldsgjá, a stunning gorge in the Botnsfjall Mountain on the Snæfellsnes Peninsula, and it was an unforgettable experience. In the summer, you can walk up to it and even climb inside. The car park is just a short walk away and the path to the gorge is surrounded by a beautiful landscape. A little bit of clambering will get you to a small waterfall, but to go further you'll need to be fit and equipped with waterproof clothing.