Temple of Crossing Roads has two portals, one going to Triana spawn, and the other going to Frostenhorn
The yellow portal leads to Frostenhorn an area where you can earn almost any achievement, but it will be upgraded when time comes, for better accessibility, and more achievements to be earned.
The blue portal leads to Triana spawn where you will find a pillar right ahead of you. Triana spawn is placed on a floating island, so don't fall off! About the pillar, behind it is another portal leading to Triana city, The RPG-part of Shiverthorn. Behind you is the portal back to Temple of crossing roads.