Pelargir:

A harbour on the mouths of the Anduin river, this was the location of the King's fleet and also subject to attacks by the Corsairs of Umbar.

Parth Galen:

The lawn where the Company of the Ring camped above the Falls of Rauros before the Company was broken.

The Prancing Pony:

The Inn at Bree where Frodo, Sam, Merry and Pippin stayed the night. The Prancing Pony was owned by Barliman Butterbur.

The Paths of the Dead:

These were the passages under the Ered Nimrais (White Mountains) between Dunharrow and the Morthond Vale. At the time of the War of the Ring at the end of the Third Age, the Paths of the Dead were a place of fear and dread as none had returned after entering. At least one of the paths lead straight through the mountains, though there were doors and paths branching off it as well.

Presumably, some of the passages might have been either a stronghold, safe from attacks, similar to Helm's Deep or perhaps the homes of the Men living there at the time of the War of the Last Alliance. Certainly the Dead haunting them were the spirits of those Isildur cursed.

It was said that only an heir of Isildur could safely pass the Paths of the Dead, which Aragorn did during the War of the Ring, along with Legolas, Gimli and the Rangers of the North.

It is likely that once the Dead had fulfiled their oath, the Paths became safe again, though doubtful that many ever used the passages again due to the memory of the danger.

The Hobbit
The Lord of the Rings
The Silmarillion
The Complete Guide to Middle-Earth by Robert Foster
The Unfinished Tales