Every Magic School was protected by Anti-Disapparition Magic, Unplottable Magic, and other spells, and Durmstrang was naturally no exception.
Because Durmstrang openly taught Dark Magic, the spells it cast to protect the school were even tighter than those of other schools.
If guests wanted to enter Durmstrang, they needed a handwritten letter from a professor before they could find the entrance to Durmstrang's gates.
In certain extreme circumstances, Durmstrang's professors would cast the Obliviation Charm, erase parts of the guests' memories, and then send them away from Durmstrang.
Snape knew what he should do now. He took a deep breath, recalled the contents of the note Voldemort had written, and only then strode resolutely into the valley.
Ripples stirred in the air, as though someone had lifted an invisible curtain, and within the originally empty, desolate valley, the outline of a castle appeared.
This castle had only four floors. It was not as towering as Hogwarts Castle, and gave off a heavy, oppressive feeling.
Whether it was the castle's dark gray walls or the outer walls standing around it, their surfaces were covered in cracks of varying depths. Smooth blocks of ice like crystal were embedded within the fissures, glimmering with a faint, cold light.
Durmstrang's school gates were even more exaggerated. Huge cracks spread from the tops of the goalposts all the way to the bottom, and ice had likewise frozen within the fissures.
The outward-jutting ice was sharp and fierce, both like crystal-ice Giant Swords thrust into the stone pillars and like strange thorns woven from stone and ice.
As Snape drew near, the black iron gates slowly opened, revealing a broad road paved with fine gravel inside.
As Snape walked along the road, he could even hear the "crack" of ice grains being crushed underfoot.
In front