Lantern Caverns are numerous mini-dungeons scattered about the Hyrulean landscape in Twilight Princess. After using a Bomb, Bomb Arrow, or the Ball and Chain on a cracked depression in an otherwise normal rock face, these caverns will reveal themselves. They are likely to contain Poe Souls, Pieces of Heart, and large amounts of Rupees, considering their expansive size and dank innards. While Link can navigate some maze-like portions of such caverns without a light source, the growing darkness, enemies such as Poes and Rats that creep in the shadows, and obstacles such as large, flammable spider webs all work against Link, impeding his progress and eventually requiring the use of the Lantern for navigation.
The first of these Caverns is in Faron Woods, and serves as a path connecting two big portions of the forest. It's the shortest and least complex of the Lantern Caverns and, unlike the other two, it's mandatory to cross in the game since it gives the young hero access to the first dungeon, the Forest Temple. In fact, it's crossed at least three times: The first is to rescue the children from Ordon Village, the second is to retrieve some Tears of Light (Wolf Link can dig up a shortcut that allows him to skip most of the cave), and the third is to go to the aforementioned temple once and for all. After Link beats the Lakebed Temple, he can warp beyond the exit of the cavern, meaning that he won't need to explore it anymore.
Another Lantern Cavern can be found on the west side of the Kakariko Gorge. The lantern proves to be a must-have item in this cavern due to the fact that each time Link encounters a fork in the path, the paths will be blocked off by a spider web that can only be removed with the use of the lantern. Along the way, Link will have to fight against Skulltulas, Deku Babas, Keeses, Poes, and Rats. Choosing the correct path will reward the young hero with a Piece of Heart.
The largest of the Lantern Caverns is located on Lake Hylia. It is found behind a cracked boulder that must be destroyed with a bomb. It is the only one to provide a portal halfway through that will send the young hero back to its entrance if he steps into its light. As with dungeons, however, there is only one entrance, and thus upon reaching the end of the cavern, Link must backtrack to return to the mainland. Inside this cavern, Link will have to make extensive use of bombs as he navigates through the maze-like cavern since in each room that he encounters, he will stumble upon four paths all blocked with a giant boulder. Only by bombing these giant boulders will the young hero be able to know which path takes him deeper into the cavern, eventually reaching the exit containing a Piece of Heart. Various chests housed throughout the cavern hold bombs, arrows, Rupees, and slingshot pellets. Enemies such as Beamos, Tektite, Keese, Poe, Chu, a few Dodongos and many Torch Slugs inhabit this cavern.
There are also differently themed caverns that are similar in purpose to the lantern caverns. There is one northeast of the Bridge of Eldin that is only accessible after collection of the Clawshot, as it's over an otherwise inaccessible gorge. Inside, the young hero finds what seems to be a branch of the Goron Mines, as it's also equipped with electromagnets. In fact, Link must use his boots so that, when falling, he is attracted by the active cranes; this is because the objective is to descend to the bottom, but carefully, in order to avoid falling into lava. Some enemies make presence here as well. Unike in the traditional Lantern Caverns, Link only needs to make use of his lantern once here, as it's necessary to unveil a chest containing a Orange Rupee. Another chest contains a Piece of Heart.
Finally, north of Hyrule Field is a frozen cavern (blocked by a bombable wall, as well as by an ice block that can only be destroyed with the Ball and Chain) where Link must solve three block puzzles. In each case, Link has to press and hold a slacked switch (two in the case of the second puzzle) with one of the blocks. Because of the frictionless iced floor, Link has to constantly push the blocks so that one of them presses the switch. Unlike the other caverns, this one makes no use of the lantern, but the reward for its completion is the same: A Heart Piece.
Alternately, Wolf Link can use his senses to provide a minimum amount of light; regardless, it is still enough to get through the mini-dungeon. If he were to come across a spider web, he can easily revert to his human form and use either a bomb or the Ball and Chain to finish the job. Note that Link cannot use his bombs to light torches, making them all pointless to visit, with the exception of the one at Lake Hylia, which hosts several hundred Rupees.