The nature within a mile of the location you stand when you cast this spell converts itself into an area of untraversable terrain. Nature will begin to quickly reclaim any non-natural structures in the area. Any creature within the area affected by this spell when the spell is being cast becomes aware of the changes that are soon to come. Any creature that does not leave the affected terrain will be magically trapped in this area and any ability check made to navigate/escape this area had a +15 to its DC (the DC cannot go above 30). For a creature with any class levels in druid or ranger, the DC drops to +10 and any spell they cast that has the ability to help a creature navigate will reduce the DC by 1 (to a minimum of the original DC). A creature cannot travel magically into, out of, or within the affected area unless the caster of the spell names that creature specifically during the casting of this spell. A creature in the area of this spell must spend 4 feet of its movement for every 1 foot it moves. If a creature takes the dash action or moves more than 60 feet in one round of combat, that creature must make a strength saving throw or be knocked prone by branches and tripping roots. If a creature fails this save by rolling a 5 or lower then that creature is also restrained by vines until the start of its next turn. A creature may use its action to attempt to break another creature out of these vines. A prone creature in this area has a movement speed of 5 unless its speed is already lower. Standing up from the prone condition in this area takes all of a creature's movement instead of half. 

If a creature takes a long rest in the area of this spell it only recovers half of its hit dice and when it finishes its long rest it must make a strength saving throw or be restrained by thorns and briars that suddenly sprout up in the immediate vicinity. A creature restrained in this way may use its action to repeat the saving throw with disadvantage. On a failed save, the creature takes 6d6 bludgeoning damage and 3d12 piercing damage from the thorns and grasping vines. 

A spell such as dispell magic can clear a small area within the area of this spell, the size of the area is a cube with a side length equal to 10 x the level of the spell slot used. A successful casting of counterspell targeting the caster of this spell when the spell is being cast allows the creature that cast counterspell to control who can use magic to move throughout the area affected by this spell but only if that creature is willing to complete casting this spell.