at Namsos and one right out in the mouth of the fjord at Røyrvik. The region of Nord-Trøndelag was quite an important region during the Viking Age. Nidaros Cathedral, if there is one place that attracts tourists like no other in this region, then it is the Nidaros Cathedral. North Trøndelag has two national parks: Gressåmoen in Snåsa and Børgefjell National Park (which is shared with Nordland). The products are top quality and the slow growing Norwegian forest produces strong, first-class timber. Several thousand spectators relive the dramatic days of 1030 through a magnificent performance involving actors, choir and orchestra. The special Trønderlag building style comprising large, long dwelling houses dominates the cultural landscape. North Trøndelag on a fine summer day would surprise anybody. In the summer months, around 250.000 people visit this cathedral, so it can become busy at times. The length of the growing season is determined by the temperature, and thanks to the Gulf Stream, agriculture thrives even in the most northern areas of mainland Norway. Olavs day, the battle is re-enacted. Around 2,500 Germans and their prisoners were living in Stabben fortress. Aker Verdal is an example of how the petroleum industry has brought new growth to the region. Gartland lies about 6 kilometres (3.7 mi) south of Harran. Nord-Trøndelag is partially an agricultural region today, as a lot of grain is grown in the very fertile lowlands of Nord-Trøndelag.