Vertically Stacked Dimensions

The portal machanics

This image illustrates how the portals represent adjacent blocks in the neighboring dimension as well as how Entities (colored boxes) are teleported between them.

Staircase (lower part)

The same staircase on the other side of the portal (top of the nether)

Portal staircase (upper part)

An underground staircase that passes through the bottom portal layer of the Overworld.