Something that is not really there (physically)?

Aii bad choice.. this is going to be a bit too hard philosophically and scientifically. It the way it is presented in the story it has no physical form (though it could be given one) but it can be sensed which may presuppose a sort of physical existance. I bet you wish you hadn't asked. *brain aching and muttering about the phenomenon v. noumenon*

Is it specific to a certain place?

Not limited but it "appears"in the book at a certain place if that helps.

Is it a "proper noun" (has a name, begins with a capital letter, etc)?

Yes it does.

Is it made/activated by a person?

the hröa and the fëa?

Galadriel - yes itis! Well done
BG no it isn't but thanks for joining the lunacy!

I can't help thinking about the Girdle of Melian. Is that it? If not, I have some other ideas...

I would class the Girdle of Melian as location specific - though presumable Melian could exercise her power anywhere,

So, no it isn't.

Is this activated during the First Age?

No it didn't exist at all in the first age.

Ah, ok. I've been thinking about Lammoth, but that cuts it short. I think I'll narrow it down a bit more...

Is it made/activated by an Elf?

Originally made by an elf/elves but not in the form we see it in the books. Not "activated" by elf in story - but no doubt done so at other times but probably in original form.

Lammoth... not a bad idea but ...

Is it language-related?

Now I keep coming back to the writing on the Doors of Moria, but the letters have a physical form, so I'm perfectly confused. :)

It is language related. Couldn't be more so really. I dont' think you are far off. The thing could have a physical form but doesn't have a single specific one.

Is it a form of writing?

no.

Is it a language?

not a language... but I think you are on the right track

Is it a spell/incantation?

Noooo but very close and if you look at the origins of the word incantation it might almost be a yes.

*searches incantation*

A poem or song, perhaps?

Yes!!! Now it shouldbe easy for you to decide which.... :D

Made by an elf, but not sung/said by one...

The ann-thenath about Luthien?

Noooo but ssoooooooooooooooooooo close.

The Gil-galad song?

The fall of Gil-galad indeed - translated from the elvish by Bilbo and sung by Sam... sorry I won't try funny stuff again!

Why not? It was a nice one! :D

I remember doing a song some time ago, but it was a much lesser known one - Narsilion, I believe.

Ok, I'm ready. Ask away!

Not for me..when I was debating internally if soundwaves were a physical presence... OK get my bugbear first

Place?

Can it be touched?

Place - no
Can it be touched? - yes

living thing?

Place - no
Can it be touched? - yes

Living thing - yes

ambulant?

Place - no
Can it be touched? - yes
Living thing - yes

Ambulant - yes, very!!!

A horse?

Place - no
Can it be touched? - yes
Living thing - yes
Ambulant - yes, very!!!

A horse? - no, but on very good track ;)