Gandalf is in Mirkwood, at the fortress of Dol Guldur. He went there with the White Council to drive the Necromancer out of Mirkwood.
the necromancer
Legolas was the son of the Elvenking of Mirkwood, King Thranduil, and thus is technically a prince, though he is never titled as such in either book or film.
They were captured several times, by the trolls, orcs, and Mirkwood spiders, respectively. But they were taken prisoner and kept in the dungeons by the Elves of Mirkwood (which is probably the instance you mean).
Thranduil is the Elven King of Mirkwood, and father of Legolas.
Sauron's stronghold in Mirkwood was Dol Guldur, or "Hill of Sorcery" in Sindarin.
There were forest elves living in Mirkwood. There were also large spiders nesting in the forest.
Gandalf is in Mirkwood, at the fortress of Dol Guldur. He went there with the White Council to drive the Necromancer out of Mirkwood.
Mirkwood.
Very dark.
the necromancer
The nights in Mirkwood are dangerous and wicked. You can’t light fires because you will be watched by giant spiders.
Legolas was the son of the Elvenking of Mirkwood, King Thranduil, and thus is technically a prince, though he is never titled as such in either book or film.
mirkwood forest
Fat Bombur.
The nights in mirkwood are dark, dangerous, and mysterious. The dwarfs can't light fires because of the eyes all around, and they could be risking their lives.
They were captured several times, by the trolls, orcs, and Mirkwood spiders, respectively. But they were taken prisoner and kept in the dungeons by the Elves of Mirkwood (which is probably the instance you mean).