Which locations have the most and hardest enemies in Skyrim to assist levelling up?
There not many enemies that are more tanky than Draugr Deathlords/Overlords and Forelhost is one of the larger of the Nordic Ruins. If your goal is to level up skills, you mostly just want to face enemies with lots of health as skill advancement is based on damage dealt so sticking with Draugr is probably a good idea as they have more health than some of the other typical enemies you find in the game.
If you want to fight hard and annoying enemies, the Dawnguard DLC adds the Falmer Warmonger to most areas where Falmer can spawn. They are very tanky and hit hard.
You can try searching through the various lists of ruin types on UESP for more ideas:
- Nordic Ruins (Lost Valley Redoubt is a great area filled with Forsworn)
- Dwarven Ruins (Blackreach is an extremely large zone, as is Mzulft)
- Caves (The DLCs adds a lot of largish caves, the Dawnguard DLCs adds Falmer infested areas in large numbers, like the Darkfall cave/passage)
You can also go Dragon Priest hunting as they're typically in medium/large burrows with large amount of Draugr.
There was a poll done on the hardest locations here:
https://gamefaqs.gamespot.com/boards/615803-the-elder-scrolls-v-skyrim/68628790
The poll did not yield many votes, but, with some research on UESP and reading round, these are generally considered the hardest. I have tested them with regard to how effective they were to levelling up:
- Forelhost [Nordic dragon priest lair, min level 24: a whole load of Draugr Deathlords and Overlords, esp at the end you will have to fight four Draugr Deathlords simultaneously and the dragon priest Rahgot. Tested - very effective {+2 levels}]
- Volskygge [Nordic dragon priest lair, min level 24: as above, but fewer. Tested - effective {+1 level}]
- Darkfall Cave / Forgotten Vale - [Falmer cave / region: a load of falmer of all levels + frost giants [the latter do not respawn]. Tested - effective {+1 level}]
- Tolvald's Cave [Falmer cave, min level 16: falmer of all levels. Tested - effective {+1 level}]
- Sightless Pit [Dwemer, min level 18] [tested - not effective]
- Lost Valley Redoubt [Nordic ruin / Forsworn] [tested - not effective]
- Morvunskar [Mage fort, min level 8] [tested - not effective]
- Ansilvund [Nordic, min level 8] [tested - not effective]
- Arcwind Point [Nordic, min level 6] [tested - not effective]
All of these respawn within 0-30 in-game days. One can therefore rotate between the effective locations using them to level up.
Of course, it also depends on how ones plays these areas - levelling up 2+ skills at a time [by making one or more legendary if necessary] is obviously going to yield better results.
Labyrithian and Bthardamz are often mentioned, but these locations do not respawn. Referring to the answer given by the user l I, I have looked at [and visited] many of the medium-large caves/dwemer ruins/tombs and found them to be largely ineffective - even though they may have multiple enemies, these locations were often level-locked so made little difference in late game. Also most of the dragon priest tombs do not respawn [there are three that do, in addition to the two given above there is High Gate Ruins, but this is not a difficult tomb to clear].
Furthermore, if one mods, or even going vanilla, one may consider the acclaimed "High Level Enemies" mod on Nexus as a sole addition, which adds more scaled enemies for all types and should be enough to keep things interesting.
EDIT: In the end I was on the right track with the tombs but doing things wrongly - one does not needs hordes of draugr to level up a warrior-like character, one single draugr is enough if you play a defensive game with it. I came across a Draugr Death Overlord in Arcwind Point yesterday and, through using a combination of block, light armour and restoration [having made the first two legendary], managed to level from 78-80 in about 15 mins. I will select this as the right answer since I solved my own issue, though user4951 still keeps the bounty since his answer was interesting and gave me lots to think about [and also the bounty can't be changed, but he would have kept it regardless since I appreciate his effort].
I am the level 314 guy here. So you want to level up some skills to make legendary?
Then finding hard dungeon is NOT the way.
Rising one hand and two hand and archery is very difficult and take a long time.
Instead, do one of these two.
With restoration glitch.
There are plenty on videos and details on how to do so https://www.google.com/search?channel=crow2&client=firefox-b-d&q=restoration+glitch+skyrim
Technically, it's lore friendly.
With restoration glitch, create fortify enchanting potion. Something like 10k % is enough. Now, after that, enchance one ring with enchance alchemy.
Now use that ring anytime to create potion. Here is the trick.
Speech, alchemy, smithing and enchanting have this rule. Your skill increase proportional to the value of items created.
That means, with 10k% fortify alchemy, for example, you can create one potion and if that potion worth 500k septim (I'll write that $500k, assuming one septim is about one dollar), you will increase your alchemy from 15 to 100 with one or two potions.
After that? Sell the potion. Again, each time you do so, you increase speech from 15 to 100.
Of course, you can also do that with enchanting and smithing. However, that's a bit more difficult. It's much easier doing it with alchemy.
Fortify restoration is a must. You get an OP character that can one shot everything. Unfortunately, even though you have 10k% improved archery gauntlet, you don't increase archery from 15-100 at one shot. So archery is not like speech and alchemy.
Without restoration glitch
Bbbbbbbbbbuuuuttttttt you're a pious lore friendly guy that wants to do this without glitch.
You can.
Max out your illusion skill. Illusion is the only school of magic I know that works. Maybe other works too I don't know. Get the master spell harmony.
Now go to a place with lots of people. I usually went to basement of solitude. However, if you know any other places, that's good too. Make sure it's a lot of people there peacefully.
A good complement of this answer will be such places. Basically, I have completed storm cloak campaign and all the defeated jarl is in the basement of solitude so it works for ME. Not necessarily for you.
Now cast harmony 7 times. Yap. Just 7 times. And you will increase illusion from 15 to 100. At less crowded places you will have to do this, 8 times. You can wait 1 hour if you run out of magicka. I simply used a helm with 10k%+ magicka so not an issue for me.
Took like 30 seconds per try.
That way you get a huge level fast.
You see the pic I showed? It shows how I make alchemy and speech legendary so many times. Then I also make illusion legendary like 4 times.
By that time my level is already so high and I got all the perk. I actually have to weaken my character and fight naked for the game to feel normal again. Otherwise, I just one shot everything.
So diplomatic immunity quest is just so easy for me. He he he he.
Other ways to increase skills
Other answers say you got to pick a tanky or tough opponent. I totally disagree. The best way to raise skills is NOT to kill tough opponents but weak opponents. Your skill increase in one hand, two hands, destruction, and archery does not depends on how tough your opponents are. It depends on how much the base damage of your weapons are.
In other words, unlike in most games where you have to fight top opponents to increase skills, in Skyrim, you can just find weak enemies and practice there. That is. Mudcrab, spiders, animals. Mammoth are fine. You want to beat up the enemy several time.
So bound sword, bound axe, and bound bows, all have near the top base damage in the game. You do not increase skills faster by enchanting or smithing your weapon. Hence, I suggest using unimproved weapons or bound weapons.
I think bound bows have like the best DPS in the game. Bound sword is close to the best sword out there. Bound axe is also near the top. The top two hand is Dragon Bone Warhammer according to this.
https://www.eurogamer.net/articles/2017-11-16-skyrim-best-weapons-ranked-best-bow-sword-dagger-and-more
Because I like to raise all skills to 100, I use Dragon Bone Warhammer to increase my two hand. After that, I do NOT want to make that legendary.