Wall of Lava

You create a wall of molten rock on a solid surface within range. You can make the wall up to 60 feet long, 30 feet high, and 3 feet thick, or a ringed wall up to 30 feet in diameter, 40 feet high, and 3 feet thick. If a creature would be enclosed by the wall, it can make a dexterity saving throw to use its reaction to move up to half its movement speed so that it is no longer enclosed by the wall. The wall lasts for the duration. 

When the wall appears, each creature within its area must make a Dexterity saving throw. On a failed save, a creature takes 9d8 fire damage, or half as much damage on a successful save.

Each creature that ends its turn within 15 feet of the wall takes 4d8 fire damage. A creature takes the same damage when it enters the wall for the first time on a turn or ends its turn there. The other side of the wall deals no damage.

The wall is semisolid, and a creature can expend 10 feet of movement for every foot of wall to move through it. Doing so causes the creature to take 10d8 fire damage, and if the creature ends its turn in the wall, it takes an additional 7d8 fire damage. 

After concentrating on the spell for 5 rounds, the wall begins to cool and cannot be moved through. Any creature within the wall at this point must succed on a strength or dexterity saving throw to push itself from the wall, taking 4d6 bludgeoning damage, and 4d6 fire damage and becoming restrained by the wall on a failed save. A restrained creature can make a strength saving throw at the start of its turn, extricating itself on a success. 

If the wall takes cold damage, or is immersed in something sufficiently cold at any point during the duration of the spell, that portion of the wall behaves like a tile in the spell wall of stone.

After concentrating on the wall for the entire duration, it no longer gives of heat or deals fire damage, having cooled. Instead, it becomes permanent and behaves as a non magical wall of stone, as per the spell.