Dunderdalen is a valley on Wedel Jarlsberg Land within the Sør-Spitsbergen National Park, on the southwestern part of Spitsbergen, Svalbard. The valley has a length of about 16 km, and opens into Dunderbukta. ... Found on http://en.wikipedia.org/wiki/Dunderdalen
1) Valley of Svalbard 
Dunderdalen is a valley on Wedel Jarlsberg Land within the Sør-Spitsbergen National Park, on the southwestern part of Spitsbergen, Svalbard. The valley has a length of about 16 km, and opens into Dunderbukta. ...