I was in Trevas Watch doing the quest there and after eliminating the 3 guards at the top of the stairs. I went a little bit further and ended up fighting 8 bandits at one time. Has this happened to anyone else. There was a Bandit chief, Bandit Maurauder, 3 Bandit Outlaws and 2 of the other 3 were scorcerers.

Actually yes and generally with more than one Bandit chief at a time. I think my highest body count in the one particular hallway ( where the sleeping quarters are) is 15. One of my thief characters never could get through their on her own... she had to hire Marcurio, Jenassa and get Uthgerd as followers to make it through that one hallway.

There are lots of places where you can have that many attackers on you, if you're not careful. Good luck if you get that many Falmer after you, for instance.

Become ethereal+fire storm seems to work wonders when surrounded

Fighting the Chief & Marauder side by side was quite challenging. The two sorcerers with lightning and frost spells were just as challenging. I know what you mean about Falmer. In Nchuand-zel after you have reactivate the dwemer machines all of the Falmer respawned at once as well. I had cleared the entire ruin of Falmer. Then I was all the sudden being attacked by 3 Falmer and a Dwarven Centurion. (I was also almost out of health potions)

I just realized I've never done Treva's Watch with a fighter character. On my stealthy characters, those 3 first bandits are usually the toughest hurdle; otherwise it's super-sneaky-shooty-stabby all the way. My mage characters all had Fury/Frenzy with appropriate perks, which helped cull the numbers a bit. Will have to try it with my "dark valkyrie" and see how it goes...

For some reason, I frequently get into a massive free-for-all just east of Riften. A small handful of mobs will ping red as soon as I leave the gates, but won't approach. Staying stealthed won't "drop aggro," and the guards make scaredy-cat noises like they do when Hired Thugs decide to teach you a lesson. If I investigate, I'll find 4-6 vampires or bandits running around randomly, and if I engage, I'll often get the attention of another 2-4 wolves or spiders. Nothing unmanageable, but then I can always slink away if I don't have a follower or a Fury spell, so maybe it doesn't count.

But the worst by far is that one solitary mage "Challenger" who rapid-fires Fireballs at you at point-blank range. I hate that guy. I think I've defeated him once, only because I happened to have the Become Ethereal shout already selected, and because I instinctively spam 'Z' when I panic.

treva's watch is tough. for my (rather stealth and ranged) character, i found it easiest to stick to the surrounding rocks outside, lure as many of them as possible out with "throw voice" shouts and await them with arrows and flame atronachs

There's a pretty nice reward for Treva's Watch so it makes sense that the place is full of baddies.

I've tried it many different ways (starting at the front gate, starting at the secret entrance, warrior build, sneaky build, mage build) and I can't remember getting through without being killed, or at the very least, retreating over and over to recover. I generally don't use followers.

It's one of my favorite locations - can't wait for a build to 'come of age' and tackle it.

Speaking of tons of Falmer all over you - Liar's Retreat is a real meat grinder. I think, perhaps, it's the toughest fight in the game just behind Alduin at The Throat of the World.

Treva's Watch is definitely one wants to be well-prepared for before going in. Yes, and Liar's Retreat as well.

For a sneaky character its fun to line up some bear traps and runes in the hallways of Treva's watch.

Depending on how a character approaches the central Bastion in Blackreach, Falmer and Falmer Servants can be overwhelming.

Forelhorst with 6 or so Deathlords all attacking at once.....all alone with only 5 restore health potions....now that was a battle worthy of song!

oooh don't remind me... took me half a night to even make it out of one particular water basin in one piece in there )

Treva's Watch always seems to have a bunch of bandits rush, and destroy you.

If you're a mage, try blocking them all by casting a Frost Atronach in front of them while they are coming at you in the corridor, then blast them with Ice Storm.

"I killed 7 in one blow!"

Sorry, that kept coming to mind as I read the post title.