Cair Andros:

An island fortress north of Minas Tirith, belonging to Gondor, Cair Andros is shaped like a ship facing upstream. The name means Ship of Long Foam.

Caras Galadhon:

The chief city in Lothlórien.

Cirith Ungol:

The Spider Pass, near to Minas Morgul on the borders of Mordor. Cirith Ungol was the route chosen by Frodo, on the advice of Gollum, to enter Mordor. It was a high, narrow pass overlooked by a fortress at the top. As an added safeguard, there lived Shelob, the greatest of the giant spiders remaining in Middle-Earth. The route through Cirith Ungol, included two very long stairways and a branching orc tunnel where Shelob lived.

Carn Dûm:

A fortress and city of the realm of Angmar. The only recorded mention of the city is after the Hobbits escaped from the Barrow-Wight.

Cardolan:

One of the three regions that Arnor was broken into in the year 861 of the Third Age of the Sun. The other two were Arthedain and Rhudar.

The Dúnedain of Cardolan fought the forces of the Witch-King of Angmar until they were forced to flee to the Old Forest and the Barrow-Downs in the year 1409. They were able to return soon after and the Dúnedain inhabited the country again until the Great Plague of 1636. After that the region was no longer considered to be a country. However, there were still settlements in existence until the War of the Ring and perhaps after.

Cardolan was the region between the Baranduin and the Gwathlo-Mitheithel and south of the East Road.

Crickhollow:

The cottage that Frodo Baggins bought in Buckland after he sold Bag-End as a part of his plan to leave the Shire. Who he bought the house from is not said. Frodo only stayed there overnight the one night, before leaving again. A few days after the four hobbits left, the Black Riders discovered thre place and broke down the door.

Crickhollow is not mentioned again until after the War of the Ring, when it was named as the place that Meriadoc Brandybuck and Peregrin Took lived.

Combe:

One of the villages which made up the Bree-Land, Combe was apparently a little further away than the others. Combe is described as having been located in a deep valley somewhat to the east. As with the rest of the Bree-Land, the village of Combe was inhabited by a population formed of both Hobbits and Men.

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