As a significant part of the casting of this spell, the caster will enter a trance and experience a dream-like condition.  While in this state, the caster will mentally design a small demi-plane on a pocket dimension.  The caster will choose the style and make up of the terrain, such as mostly ocean with small islands, a forested area surrounded by a desert, a mountain with a network of tunnels underneath, and so on.  (The details must be provided to the DM at the time of casting)  The spell can only create a natural terrain, and will not bring about any type of structures.  The caster will choose the type of climate that exists in this demi-plane, such as mostly sunny, blizzard, light fog, light rain, heavy rain, or a perpetual cycle through multiple types of weather.   Once the spell ends, the components are consumed and the domain comes into being.  A caster may only have one domain created at a time.

Initially upon casting this spell, the domain will be in a spherical shape with a 1/4 mile diameter.  It can be increased in size by casting the spell multiple times (8 hours each time), though the material components are only required the first time.  Each time it is cast, the area increases by a 1/4 mile, to a maximum of 2 mile diameter.  At any step during its creation, the caster can choose to make the domain permanent and cannot be dispelled by anyone other than its creator.  (Each time it is cast, more details can be provided to the caster).  Casting this final ritual means that its make up cannot be changed in any way, other than through physical work such as building a castle or tunneling through rock.

When the domain is completed, as part of the final ritual casting, the caster creates a spell that opens a portal to this domain.  Casting this spell becomes a 1 minute ritual, has a range of 20 feet, and a duration of 10 minutes or until the caster loses concentration.  The portal remains open for the duration, though the caster can choose to close it early by removing concentration upon it.  Any creature or object that goes through the portal exits in the location on caster's domain that they choose to as part of the casting.  To exit this domain, another instance of the entrance spell must be cast again, though this time it will only take an action to cast.  Exiting the domain will always be to the spot the entrance spell was cast to enter the domain.