A sightseeing route running through the Tateyama mountain range in the Northern Alps opened Monday, offering views at one point of snow walls as high as 17 meters on each side of the road.

"I was so surprised at the size. I guess we cannot see such a high snow wall anywhere else," said Yusuke Ogura, 32, who came all the way from Wakayama Prefecture to experience the snowy passage.

The Tateyama Kurobe Alpine Route, which connects the town of Tateyama in Toyama Prefecture with the city of Omachi in Nagano Prefecture, is popular for its spectacles of mountains, valleys and waterfalls.

Until June 22, visitors can walk along a pathway next to the walls, which are created by snow-removal vehicles and dubbed the "Yuki no Otani" (Great Valley of Snow). The road winds through the Tateyama Murodo plateau at an altitude of 2,450 meters.

The opening of the 37.2-km sightseeing route this season was delayed by a day due to snowstorms.

Given the growing tourism boom, the operator of the route expects 1 million visitors, up about 70,000 from a year ago, to show up this year before the tourist season ends in November.