Portals are magical gateways through the very fabric of reality itself. Portals may be created through some class skills such as Groves, Crystalism, or by certain powerful artefacts such as the Wand of Portals. Most of these magical portals can be blocked or slowed by the use of a Monolith sigil.
There also exists the Ring of Portals on Loom Island which are used by newbies to reach various locations throughout the lands.
This should talk about grove portals, planar portals, Wands of Portals, etc.