Field of Blades

This is why they didn't call it "*Limited* Blade Works".

The Field of Blades seems to be the representation of Endless Struggle and Utter War. It's a desert with swords sticking in the ground by their blades. The battle seems eternal for whoever walks it.

It's most likely a graveyard for warriors with swords standing in for proper headstones.

Examples of Field of Blades include:

Anime and Manga

We see Ichigo sitting in the Field of Blades in the Opening Sequence during the Soul Society Arc of Bleach. Small wonder; he has an endless battle ahead of him, having decided to take on the entire afterlife for the soul of a friend. We also see the field during his inner struggle to awaken his powers and those of his sword.
- And during his less-inner struggle to awaken his Super Mode, Ichigo's mentor forces him to search for his real sword in a literal field of fake ones. While being assaulted by the very sword's spirit.
Part of the opening sequence of Samurai Champloo..
In Samurai 7, during the first battle with the bandits, the experienced leader sticks numerous swords into the ground in case someone's happened to break, as he wants them to fight to the fullest.
Variation: The third intro of Naruto suggests the trope with a field of kunai.
In Berserk, Rickert creates one of these as a memorial for the Band of the Hawk, personally forging a sword for each of the fallen. Ironically, it is on this hill that Guts encounters Griffith, the bastard who sacrificed and betrayed the Hawks, reincarnated as a human again for the first time since the Eclipse.
Variation: In the 1st ending of the second season of Mobile Suit Gundam 00, Setsuna F. Seiei is seen standing in the middle of a field of guns standing barrel down in the ground, all of which are covered with some sort of flower.
The Rurouni Kenshin manga spoofs this trope a bit. When a government official is targeted for assassination, he hires various swordsmen to protect him—but at the same time, he insults and belittles their skill and brags about how he stood against "the field of blades and the storm of arrows" during the Meiji Revolution. Just then, Kenshin walks in, politely remarking that he has not seen the official since Kenshin CARRIED him through "the field of blades and the storm of arrows," as the official was too busy cowering in fear at the time to lend a hand. This promptly shuts the official up.
- Played in a more serious manner whenever Kenshin's history as Battousai shows up: in the beginning of the manga, in the end of the Tsuiokuhen OVA, and in the upcoming live-action film, katanas are planted amidst the bodies of the fallen combatants.
In Claymore, there's a minor one after the timeskip. There's only seventeen blades, but the first scene it shows up in certainly qualifies.
In Gurren Lagann, in the burial place of Kamina his sword is sticking out of the ground by the blade, his cape tied to its handle. In the Distant Finale, after the death in space of most of the Dai Gurren Brigade, several other swords stand alongside that one, as well as a needle standing for Nia.
In Soul Eater, Mifune's sword-style Mugen Ittoryu relies on him throwing all of his swords up into the air, so that they fall to earth and pierce the ground in this manner.
Rave Master had a battlefield made into a memorial by turning it into a field of blades.
Might not count, but in Shaman King, one of Ren's attacks with his third oversoul is "Blade Paradise", where thousands of oversoul blades burst through the ground and demolish his opponents.
In Katanagatari, this is how Meisai uses her Tsurugi, attaching each of the thousand swords to a tree. Then it's averted when Shichika just runs out of the forest.
Sequence 1-8 of Magical Girl Lyrical Nanoha Movie 1st The Comics uses this imagery for its title page, with Fate standing on a rock amongst a field of spears. The next chapter's title uses this imagery again, with Nanoha standing on a cliff while surrounded by a field of staves.
In Puella Magi Madoka Magica, Mami Tomoe uses a musket as weapon, one of her attacks in nicknamed Unlimited Musket Works by the fans, guess what it does?
- Sayaka can also spawn small fields of swords so she can quickly pick them up and throw them, but Homura one ups them both. Is it any surprise that part of the development team worked on Fate/Zero?
In the manga adaptation of Yu-Gi-Oh! 5D's, Yusei has a card called 'Warrior's Pride', which depicts one of these in its artwork, with Shield Warrior (a card he uses in the anime adaptation) leaping out of the ground at the field's centre.

Comic Books

In the comic Planetary, the Big Bads have this trope in the form of an Alternate Universe. It's a featureless plane of floating weapons, but upon closer inspection the floor is made of the bones of the world's former inhabitants. (They killed an entire world just so they'd have somewhere to keep their swords).
In the Vertigo comic book series Lucifer, the entrance to the home of Lilith is marked by a Rain of Swords, which is symbolic of what she perceives as her struggle against the God who exiled her from the Garden of Eden and his Angels who exploited and waged war on her children.

Fan Works

In chapter 4 of the My Little Pony: Friendship Is Magic fanfic The Ballad of Twilight Sparkle, Rarity uses her illusion magic to conjure one of these while trying to pass off the weapons she confiscated from the Cutie Mark Crusaders (who were assaulting Spike in a poorly thought-out attempt to get dragon-slaying cutie marks) as a new fashion statement, "Shield-Maiden Chic".

Film

The Samurai 7 example above may be a nod to the final battle in Kurosawa's Seven Samurai, where Kikuchiyo explains that he needs a lot of swords to kill a lot of people. Also, the four graves of the dead samurai have swords sticking out of them.
The film The Prophecy has a fairly bizarre variation, wherein the endless field of blades is in fact an endless field of wooden stakes, on which fallen angels are impaled.

Literature

The third book in Conn Iggulden's Emperor series is called The Field of Swords.
This also happens in Brandon Sanderson's The Way of Kings when we flashback to the Radiants abandoning humanity and leaving their Shardblades in the ground. It takes all of twenty seconds before bystanders start picking them up.

Live Action TV

The promotional video for season 2 of Heroes released at the end of August 2007 shows Hiro amidst a field of katanas.
Morgana has a vision of this as her and Arthur's final end in Merlin

MMORPG

Warhammer Online has an area in the Chaos Wastes that is a battlefield covered as far as the eye (or graphics card) can see with weapons, armour (usually staked into the ground on spears) and... this being Warhammer, after all, frozen corpses buried up to their waist.

Tabletop Games

As of the Dawn Solution, Solars in Exalted have an Unlimited Blade Works-style Charm: Thousand Arms Prana. This upgrade to Summoning the Loyal Steel allows the Solar to store as many weapons Elsewhere as he pleases, at a cost of one committed mote per (Essencex2) weapons. Decommitting this cost causes all of the weapons to embed themselves in the scenery around the Exalt, intangible to anyone but him until he picks them up and starts using them. The full text of the Charm (as well as a link to the Ink Monkey article it originated from) can be found here.

Toys

Bionicle has the Forest of Blades on Bara Magna, where the remains of warriors still holding their swords and weapons are fused to the trees themselves, by the powers of the Element Lord of Jungle they were fighting.

Video Games

The aptly-named Keyblade Graveyard, the site of the Keyblade War, appearing in Kingdom Hearts II's Stinger and Kingdom Hearts: Birth By Sleep.
Tangentially related, a trap in Tomb Raider (original and remake). One of the puzzles, concerning the Sword of Damocles, has Lara making her way through a room where any step could bring a deadly sword down on her head.
In Ninja Gaiden II's trailer, Ryu Hayabusa is found holding both one of the Falcon's Talons claw weapons and the Eclipse Scythe while walking through a field of blades. You actually get to fight in this field of blades, though no serious battles occur. After killing Genshin, the rival ninja gives Ryu his cursed sword: The Blade of the Archfiend. After the credits roll, Ryu is seen praying for Genshin's soul in front of this very blade, stuck into the ground alongside the other blades. He then turns and leaves it there, a memorial for his defeated rival.
In Yggdra Union, units not killed in the initial charge drop their weapons when defeated, firmly planting them in the ground. Close battles can end up with two leaders duking it out on a Field of Blades made of the weapons their respective units used, which ends up moderately amusing when witches fight on a Field of Brooms.
Several Dynasty Warriors 5 character endings make use of the image, sometimes with bodies.
In Ninja Blade, the final boss-fight takes place in a Field of Blades. However it stays still during the fighting, the swords get thrown around during cutscenes.
The Blade Drifts of Zopheir from Tales of Vesperia.
The Edge of Madness stage invented for Dissidia Final Fantasy. The small stage you fight on is in the middle of a seemingly infinite blasted, war-torn plain filled with swords. Only these swords are easily several stories tall. And the Final Boss has a move where he gets big enough to wield them.
Bonus art for BlazBlue depicts Hakumen standing in one. Probably as a Shout-Out to Fate Stay Night.
Likewise "Infinite Graves" from Disgaea 3: Absence of Justice is also likely a Fate Stay Night reference.
One appears in Dragon Age as the main menu art.
- The two swords that stand out the most, Yusaris the Dragon Slayer and Asala Sten's missing sword can actually be found in the game.
The stage selection screen in Heavenly Sword features a variation of this: while there might not be nearly as many as your standard Field of Blades, each particular one is really big.
The Game Over screen of Fire Emblem: Radiant Dawn is a melancholic picture of a Field of Blades. (And axes...and lances...)
One of the first pieces of promotional art released for Final Fantasy X (And the first thing you see in the story) was of the characters' weapons piled up on the ground near the Zanarkand Ruins.
The grave of the Abysswalker Knight Artorias in Dark Souls. It's an open field of grass and flowers, the middle of which holds his very large greatsword, which is surrounded by many other swords and gravestones. It doesn't look guarded... at first.

Visual Novels

In Fate Stay Night, Archer is depicted in the opening as walking through a field of blades, representing his struggle with his ideals and endless conflicts. His Reality Marble (a representation of his soul) is the actual above field, wherein he has full control of all the swords and can rain down a Storm of Blades on any interlopers. His Badass Creed invokes said Reality Marble.
- In one path of the Visual Novel, Shirou also unlocks his own version of Unlimited Blade Works (pictured above). The Magical Incantation used to invoke it is slightly different from Archer's, showing Shirou's optimism and self-sacrifice compared to Archer's cynicism.
  - In both cases, the scenery is suspiciously similar to a scene from Archer's Dark and Troubled Past. It's likely the blades also symbolically serve as headstones for everyone who died in the fire at the end of the fourth Grail War, along with anyone else Archer couldn't save.
- This has undergone Memetic Mutation, with various Fan Art pictures of other characters in fields of their weapon of choice reciting an altered version of the Engrish attack phrase.

Western Animation

The Dragons' Graveyard, in the Dungeons And Dragons episode of the same name, is Exactly What It Says on the Tin, an extradimensional dragon graveyard presided over by Tiamat. Apart from being full of creepy dragon skeletons, its most notable feature is being up to its armpits in abandoned magic weapons.
In Wakfu this is what Iop heaven looks like.

Other

Older Than Steam: In the tradition of Tarot cards, the Eight and Ten of Swords both use this imagery.

Real Life

A historical example, and possibly the Trope Maker: the shogun, Ashikaga Yoshiteru was known for his skill with the katana. On 1565, when his small force was attacked by a large coalition Miyoshi force, Yoshiteru knew he was more or less screwed but determined to go down fighting. Bringing out numerous katana (Some sources say a dozen, some others say around a score or so), he plunged them into the floorboards of his castle and killed a large number of enemy troops on his own throwing aside priceless katana that broke down as their blades became notched. However, with no help arriving from daimyo that would have supported him in time, the few troops under Yoshiteru and eventually, Yoshiteru himself was overrun. This may have inspired Archer's Unlimited Blade Works, as his chant suspiciously sound like a piece of poetry from the same man.
Any depiction of the Arlington Cemetery is, in essence, a Field of Blades.
There are thousands of pictures from both World Wars and the Korean War (sometimes Vietnam War or Iraq memorials) that depict rows upon rows of rifles jabbed into the ground with the bayonet and a helmet on top.
- Dog-tags or boots are sometimes hung on the bayonet as well.
Vlad the impaler uses a different version. A field of lances with bodies impaled on them. Said to have discouraged an invading army from attacking his territory.