Complex sentence: The fjord is one of Norway's most visited tourist sites and has been listed as a UNESCO World Heritage Site, jointly with Nærøyfjord, since 2005, although this status is now threatened by the disputed plans to build power lines across the fjord.
Split into simpler sentences: The fjord is one of Norway's most visited tourist sites. In 2005, it was listed as a UNESCO World Heritage Site, jointly with the Nærøyfjorden, although this status is now threatened by the disputed plans to build power lines across the fjord.