Gelaria

Vanilla-friendly cold-themed dimension mod adding unique biomes, blocks, items, creatures, game progression and mechanics.

To construct a portal, build a 3x3 frame out of any combination of cold blocks, fill the inside with transparent ice, place an Enchanted Ice in the middle and wait for the ice to slowly convert into portal blocks. Beware that depending on the version the portal may send you to inside solid blocks or high up in the air.