Complex sentence: The most famous landmark in Langesund is Langøytangen fyr, which is a lighthouse placed on the peak of Langøya, a kilometre long island right outside of Langesund.
Split into simpler sentences: The most famous landmark in Langesund is Langøytangen fyr. That is a lighthouse (fyr in norwegian) placed on the peak of Langøya, a kilometre long island right outside of Langesund.