The land of Skyrim has a long and storied history. It is written across its landscape in its cities and crumbling temples. It is also written in its barrows, tombs that honour the dead and hold their treasured possessions. These items might not just be treasured by the ancient Nords, however.
Tomb robbing is a fun and profitable venture for a Dragonborn to engage in, for quests, items, or a little extra coin in their pocket. It is also not without its dangers. Traps, draugr, bandits, and even undead dragon priests can cause problems in your expeditions. Sometimes though, it is worth the effort.
10 Bleak Falls Barrow
The original. Most people's first attempt at delving into a Nordic tomb, Bleak Falls Barrow looms over Riverwood. It's where you are sent by Farengar Secret-Fire as part of the main quest, to recover a Dragonstone from inside.
Being one of the earliest dungeons you're likely to enter, Bleak Falls introduces a lot of things you will become familiar with later. Traps, draugr, and Dragon Claw doors will all make an appearance. There will also be a very, very big spider, and a thief at one point. Finishing the barrow will net a chest, and a Dragonstone that will lead your Dragonborn to discover their voice.
9 Volunruud
A short ride from Whiterun, you can find the tomb of Volunruud, resting place of Kvenel the Tongue. He's not resting much, but her certainly is inside, along with his legendary weapons Eduj and Okin.
The barrow itself keeps in theme with the importance of the two weapons. In order to open the main burial chamber, you must recover a ceremonial sword and axe from opposite ends of the tunnels. Uniting them in the burial chamber door will cause it to open, allowing you to face the spectre of Kvenel and claim his weapons. They deal 10 points of Frost damage to both Health and Stamina.
8 Yngol Barrow
On the south bank of the river, north of Windhelm, is a truly strange tomb — Yngol Barrow, named after the son of Ysgramor. This can be part of several quests, which may change the nature of the enemies and loot inside the tomb. Often, it will be devoid of enemies, though you will not be alone. Little orbs of light will jump from areas in the tomb, chirping and following you on your progress through. They don't appear anywhere else.
Quests aside, you can find the Helm of Yngol, guarded by Yngol's Shade. This great-looking headgear grants 30 percent Frost resistance when worn.
7 Ansilvund
A little way north of Riften you can find Ansilvund, a Nord tomb to which you're not the first contemporary visitor. Upon exploration of the barrow you're greeted with the voice of Lu'ah Al-Skaven, a necromancer who has lost her husband, and sought to revive him in the way necromancers tend to do. Failing this, she apparently wants to flood Skyrim with undead thralls in revenge. So, she's dug up the renowned ancient Nords Fjori and Holgeir and forced them to assist her.
While it's fine to feel a little sorry for Lu'ah, raising a horde of draugr to destroy the living is not the right way to handle loss, and reaching the end will pit you against her. To thank you for freeing them, the ghostly couple will gift you the Ghostblade, an ancient Nord sword with a spectral appearance, and whose extra damage ignores armour.
6 Forelhost
South of Riften, on the side of a mountain, is Forelhost. Outside, you will find Valmir, an ostensible Imperial (or possible Stormcloak) officer, who claims to be there searching for the mask of the Dragon Priest Rahgot. As often happens, he has no interest in going into the spooky tomb, and asks the Dragonborn to go inside to look for it.
Forelhost is an extensive tomb, formerly a base of operations for Dragon Cultists, and tells a dark story of the last days of the cult. Fighting through the ghosts and draugr will eventually lead to a battle with Rahgot. Felling the undead priest will yield his mask, which gives 70 extra Stamina when worn. Returning to the camp will, as his switching allegiances might suggest, show that Valmir hasn't quite been level with you.
5 Yngvild
Some tombs may be worth sacking for what they provide materially. Certainly, Yngvild has a few items that are worth taking. There's an Alteration-enhancing book, a Grand Staff of Charming, and one of the Stones of Barenziah.
There are other reasons to break in there, however. Primarily, getting to deal out justice. As you venture into Yngvild you will find ghosts and draugr, all female, along with journals from an elf named Arondil. He wastes no time showing that he is a complete creep, and that raising female undead is no coincidence. Fortunately, you can deal out sweet justice by taking the Soul Gem next to his throne in the burial chambers, releasing his control on his ghostly former servants. Then you can sit back and watch the ghost lady beat him up. Some things money just can't buy.
4 Hag's End
This barrow might not be immediately obvious. It is only accessible through Deepwood Vale, which cannot be reached from the Skyrim map. It can only be reached after crossing through the Forsworn-ridden Deepwood Redoubt. Walking through the outpost, there are various notes talking about their 'martriarch'. This should probably set off alarm bells, though it is not until crossing into Hag's End that you discover the identity of the leader.
You'll have to fight the Hagraven in various spots she transports herself to all over the ruin, concluding on the roof. On the altar there, you can find the unique weapon Bloodthorn. This dagger will fill a Soul Gem on killing a creature, and can steal a little of enemy health too.
3 Frostmere Crypt
Sat near Dawnstar, approaching Frostmere Crypt will present you with the odd sight of a bandit named Eisa Blacktorn being attacked by some of her former colleagues. If Eisa survives the encounter, she mutters something about her friend stealing their boss's sword.
Advancing through the bandit hideout will eventually lead you to an impressive sight, a forest far below the surface. You'll find the boss in question and Eisa's friend both felled. As it turns out, the sword that was removed from deep inside the barrow already had an owner, and she wasn't overjoyed at the prospect of her possessions being taken. You can return the Pale Blade to the altar and pacify the Pale Lady, or you can send her back to the afterlife more forcefully and keep the sword. The weapon is unique, does 25 Frost damage per hit, and causes creatures under level 16 to flee.
2 Valthume
In a remote part of The Reach you can find the barrow of Valthume. On entering you are greeted by the ghost of an ancient Nord, who is in desperate need of help. He informs you that the Dragon Priest Hevnoraak is less dead than is ideal, and facing him head-on requires finding three vessels in the tomb. Tracking these down and returning them to the spirit will indeed allow the Dragonborn to take on the undead priest.
Hevnoraak, as with most Dragon Priests, is not an easy fight. Dispatching him yields his mask, of the same name. Wearing the Hevnoraak mask makes the user immune to both disease and poison, which is very handy in certain situations.
1 Labyrinthian
One of the few compelling reasons to go to Hjaalmarch, the massive ruin of Labyrinthian is a treasure hunter's dream. Not simply home to one major treasure, there are three different areas that a would-be robber might wish to explore. The winding Shalidor's Maze challenges your understanding of the schools of magic, and yields a circlet that reduces Magicka costs for spells. The tombs of Lost Valkygg are one of the earliest locations you can get your hands on Ebony weapons, if you can handle the high level draugr wielding them.
Finally, if you have collected all the Dragon Priest masks, taking the wooden mask in the central chamber and putting it on will warrant a final, hard to find reward.