D&D 5E What are the best ways to conceal an entrance/door with or without magic?

[Gardens & Goblins]

I'd stick it way out from the land, under the cold dark sea, deep beneath the waves. Nobody is going to head out there.

Also a great excuse for undead washing up on the shores and attacking the locals.

Throw in a kraken as a guardian of the entrance for good measure.

 

[5Shilling]

The "Stone shape" spell could be used to disguise an entrance, for instance as a blank wall, a natural rock formation, a statue or something else. Then there's no illusion to detect or dispel.

The same result is possible for a dwarven master stonemason but this way is quicker and more magical! The finished work could be a well hidden secret door on hinges.. or it might even be a solid wall that requires Stone Shape to open a hole and shut it again every time.

 

[Guest 6801328]

Combine the sewer idea with the old waterfall trick: not many heroes will see a cascade of fetid sludge running down a wall and think, "Hey, we should look behind that waterfall for a secret cavern!"

 

[Dannyalcatraz]

The best place to hide a needle is in a needle stack.

So hide the phylactery in a largish concealed chamber...full of phylacteries. You know, kind of like they did with the Holy Grail in Indiana Jones and the Last Crusade or the Necronomicon in Army of Darkness.

 

[Imaculata]

The best place to hide a needle is in a needle stack.

So hide the phylactery in a largish concealed chamber...full of phylacteries. You know, kind of like they did with the Holy Grail in Indiana Jones and the Last Crusade or the Necronomicon in Army of Darkness.

I had a Lich in my monster campaign hide a fake phylactery in a large central room filled with poison gas, and behind glass. So the fake phylactery could be seen from anywhere in the lair, and really drew attention to itself. It also looked ornate and really important. The actual phylactery looked quite mundane, and was hidden in a small secret room far away from the fake one, with no guards, so no attention would be drawn to it.

 

[Eltab]

To disguise a door:
- A thick layer of plaster applied all along the appropriate wall and decorated with floor-to-ceiling artwork. Ex: Egyptian hierioglyphics telling the reader how awesome and powerful the lich is.
- The circular window in Paris' Cathedral of Notre Dame, lit from behind. Surely there is no door behind this, there's just a magical Eternal Lantern in a niche.
- Mosaics (of the lich in his glory of course) show him defeating his enemies - including the dragon whose corpse he subsequently kept?
- Tapestries all along the walls.
- Many copies of his personal logo on a fake door; one logo is just slightly different. You have to cast a spell and touch the right logo to be teleported into the room behind. If you just rip off the door, there is a wall of bricks behind it (like Al Capone's Vault turned out to be).

Do this on both sides of the hallway, and on a few non-door'ed hallways too.

 

[Eltab]

Combine the sewer idea with the old waterfall trick: not many heroes will see a cascade of fetid sludge running down a wall and think, "Hey, we should look behind that waterfall for a secret cavern!"

The exception might be a Cleric (or Paladin) of Moander*...

* FR god of corruption and rot

 

[Jediking]

Place a Huge Undead Storm Giant in front of it. Local population is scared to go there from rumours of its death, and the Giant can be animated as a guardian. Conceal and defense, all in one.

 

[Imaculata]

Place a Huge Undead Storm Giant in front of it. Local population is scared to go there from rumours of its death, and the Giant can be animated as a guardian. Conceal and defense, all in one.

A Huge Undead Storm Giant isn't exactly a subtle way to hide the entrance to a lair, even if it is a powerful foe. An undead tree might be more sneaky. Something that doesn't look like a guardian, until it comes alive. Or you could make the door a mimic.

 

[Jediking]

A Huge Undead Storm Giant isn't exactly a subtle way to hide the entrance to a lair, even if it is a powerful foe.

Bah, what good lich wants to be subtle about their powers to raise even a Storm Giant?

An undead tree might be more sneaky.

...This is a much better idea. A Whomping Willow/Treant perhaps.

Or you could make the door a mimic.

The world's first and only supra-predator, the Massive Mimic! (Huge size, even huger appetite)