Sognafjorden (sông´nəfyôr´dən), or Sogne Fjord, inlet of the Norwegian Sea, SW Norway, in Sogn og Fjordane co. Extending c.110 mi (180 km) inland and reaching a depth of c.4,000 ft (1,220 m), it is the longest and deepest fjord in Norway. It has several branches that cut into the Jotunheimen Mts. and the Jostedalsbreen glacier. In some places the mountains drop a sheer 3,000 ft (910 m) to the water on both sides of the fjord. The beauty of the region has made it a popular tourist area, and there are many well-known resorts along the fjord.