haunting/dark classical


new to classical, I really like Samuel Barber's Adagio for Strings, Op 11. I am looking for other music with the same dark/haunting sound. Suggestions?
lwatson
Mendelssohn "Overture "The Hebrides" (Fingal's Cave) Op.26

Rachmaninoff "Isle Of The Dead"
All over the map here. Dark and haunting are not terms I would use to describe the Barber piece, which is one of the most-mentioned pieces in the thread "Most achingly beautiful music." Lwatson, can you expand on your meaning?
Aarvo Part's Fratres. I have the I Fiamminghi version on Telarc. Excellent music!