Minas Anor:

Minas Anor, the city of Anárion.The name translates to The Tower of the Setting Sun. One of the three main cities of Gondor, Minas Anor was renamed Minas Tirith, the Tower of Guard after Minas Ithil was taken by the Nazgûl. It became the capital city after Osgiliath had started to be abandoned in the year 1640 of the Third Age.

Minas Ithil:

The twin city to Minas Anor, Minas Ithil was the city of Isildur and its name translates as The Tower of the Rising Moon, often just called The Tower of the Moon. It was taken by the Nazgûl in the year 2000 of the Third Age and renamed, in Gondor, Minas Morgul, the Tower of Black Magic. It was a terrible place until the fall of Sauron, and judged by the King Elessar not fit to live near for long years after the War of the Ring.

Minas Tirith:

At first called Minas Anor, this city was renamed Minas Tirith, the Tower of the Guard after Minas Ithil was taken by the Nazgul in the year 2002 of the Third Age of the Sun. It later became the capital city of Gondor after Osgiliath was abandoned, and remained the major city in Gondor until the War of the Ring.

In structure, the city was built of white stone in seven levels going back into the side of Mount Mindolluin. The entire structure of the city is geared towards it's defense.

The gates of Minas Tirith were destroyed during the Battle of the Pelennor Fields, and the first circle of the city was pretty much destroyed by fire during the preceeding siege. After the War of the Ring, Aragorn made Minas Tirith into his capital city in Gondor.

Mordor:

Mordor, translated as, the Black Land, was the realm of Sauron, and where he forged the One Ring. This was Sauron's home from around the year 1000 of the Second Age, to the year 3019 of the Third Age, when Frodo destroyed the One Ring in Mount Doom. However, there were intervals where he resided elsewhere, such as the time between the War of the Last Alliance and the Quest of Erebor. In those years, Sauron first was regaining shape, and then in residence in the forest of Mirkwood.

Moragai:

The Moragai was the inner fence of Mordor, on the east. Lower than the Ephel Dúath, the Moragai was not entirely barren, with thorny bushes, harsh grasses and biting flies.

Mathom House:

A museum in the Shire, the Mathom House was located in Michel Delving. Before Bilbo left the Shire, he had loaned his mithril coat to the Mathom House to display.

Mengroth:

The home of Elu Thingol in Beleriand, Mengroth was built underground, like the stronghold of the Elves of Mirkwood. Mengroth was destroyed in the sack of Doriath.

Meneltarma:

The Meneltarma was the mountain at the centre of Númenor, used as a temple to Eru, left untouched by Men, Later, when Númenor sank beneath The Wave, it was said the top of Meneltarma remained an Island, but it was never found. Four times a year, in the appropriate times, the King led a procession to the top. This continued until the times of the King's Men, when the hallow was neglected.

Mere of Dead Faces:

The Mere of Dead Faces in the Dead Marshes was a horrible place, especially at night, which was when Frodo, Sam and Gollum passed through.
On either side and in front wide fens and mires now lay, stretching away southward and eastward into the dim half-light. Mists curled and smoked from dark and noissome pools. The reek of them hung stifling in the still air. Far away, now almost due south, the mountain-walls of Mordor loomed, like a black bar of rugged clouds floating above a dangerous fog-bound sea. (LOTR.650)

This description fits the entire Dead Marshes, but goes with the painting on the right, which is of the Mere of Dead Faces.
When lights appeared Sam rubbed his eyes: he thought his head was going queer. He first saw one with the corner of his left eye, a wisp of pale sheen that faded away: but others appeared soon after: some like dimly shining smoke, some like misty flames flickering slowly above unseen candles; here and there they twisted like ghostly sheets unfurled by hidden hands. (LOTR.652)

"There are dead things, dead faces in the water," he said with horror. "Dead faces!"
Gollum laughed. "The Dead Marshes, yes, yes: that is their name," he cackled. "You should not look in when the candles are lit."
"Who are they? What are they?" asked Sam shuddering, turning to Frodo, who was now behind him.
"I don't know," said Frodo in a dreamlike voice. "But I have seen them too, In the pools when the candles were lit. They lie in all the pools, pale faces, deep deep under the dark water. I saw them: grim faces and evil, and noble faces and sad. Many faces proud and fair, and weeds in their silver hair. But all foul, all rotting, all dead. A fell light is in them." (LOTR.653)

Minas Morgul:

Once, Minas Ithil, but was taken by Sauron and made into a place of horror:
Upon the further side, some way within the valley's arms, high on a rock seat upon the black knees of the Ephel Dúath, stood the walls and tower of Minas Morgul. All was dark about it, earth and sky, but it was lit with light. Not the imprisoned moonlight welling through the marble walls of Minas Ithil long ago, Tower of the Moon, fair and radiant in the hollow of the hills. Paler indeed than the moon ailing in some slow eclipse was the light of it now, wavering and blowing like a noissome exhalation of decay, a corpse-light, a light that illuminated nothing. In the walls and tower windows showed, like countless black holes looking inward into emptiness; but the topmost course of the tower revolved slowly, first one way and then another, a huge ghostly head leering into the night. (LOTR.730)

After the War of the Ring, Minas Morgul and Imlad Morgul were destroyed, though the valley was not safe to live in for many years after.

Misty Mountains:

But the mountains were the Hithaeglir, the Towers of Mist upon the borders of Eriador; yet they were taller and more terrible in those days, and were reared by Melkor to hinder the riding of Oromë. (S.62-63)
That was what the Misty Mountains were like in the Ages of the Stars. Though of lesser height, they were still difficult to cross late in the Third Age, as was discovered by Bilbo and Frodo Baggins. Frodo by the Redhorn Pass and Bilbo and the Dwarves by the High Pass. The Company of the Ring were forced down again by blizzards and had to attempt the Mines of Moria. The Dwarves were forced to take shelter in a cave and captured by Orcs. Both groups made it safely through the mountains though.

Mirkwood:

Originally named Greenwood the Great, and later after the War of the Ring, named Eryn Lasgalen, or the Wood of Green Leaves, once Sauron built his fortress, Dol Guldur there, the name became Mirkwood. During this time period, the forest was very dark and gloomy.
Presumably, the northern areas were not so bad as they were the realm of the King of the Wood-elves, but the southern regions were close to Dol Guldur.

According to Bilbo, in the regions of the road, the spiderwebs were huge, there were no safe sources of water, the nights were full of eyes and the animals, what few there were, were almost inedible. On top of this, there were giant spiders in some area, although, apparently the Wood-elves tried to keep them away from their realm.

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