how do i get to the one in the building and the other 1 in the place thast apparently just east of vault 108


what area in the DC should i start and what metros should i look for

(i have my O:A tank armour and the ghoul mask so im basically unstopable + i set out with a chinese assault rifle i now carry a gatling laser and a half ton of random weapons :/)

The only Behemoth in a building is the one in Capitol Building, kind of a hard to miss... You can enter either from the mall side or go from the back, Seward Square (where the crazy prophet is preaching).

The other one is propably the Jury Street behemoth. Between Jury Street station and Evergreen Mills (which also contains a Behemoth) is a Super Mutant camp, inside the camp are cages, one of them contains a teddy bear, open that cage and turn around...

Fix'd.

just opening the all the cages in the container works for me

You don't have to take the bear. If you open the cage he starts shaking and making noise. (Crying out for papa to save him?) and the Behemoth shows up. That event is sort of glitched though, the Behemoth can spawn even if you don't do anything in that area.
I've fast traveled to the metro station nearby and found the Behemoth had spawned and was mashing raiders and talon company dudes into little tiny bits.

thats the one i killed yesterday

only ones left are in the DC area capitol building and further northeast some where

Propably the Takoma Industrial Behemoth then? That is a bit hard to get to, you need to find a metro in the area where the Statesman Hotel is, it's out of the way, and leads to long, watery tunnel filled with Mirelurks. After that you emerge to Takoma Park, which is a residential area. Moving trough it gets you to the industrial area, the Behemoth is on a large parking lot.

Get ready for bloody murder through here. I always get a lot of enemies with heavy guns, from two different factions, and with all the cars parked all over the place, and me spinning Eugene constantly, I go through about 4 full mag loads for Eugene until silence returns again.

That behemoth is particularly fun. Because you can kill it by activating missiles. There is a switch nearby. The missile attacks don't always hit, but if you stay hidden and fire enough times you can kill the Behemoth and his friends without even getting a scratch (assuming you get to the missile activation switch).

ok so i do have te stateman hotel area on my map

where do i go after loading up that area ???

what do i look for ???

i watched the one in the capitol building have its leg randomly blown off :/ (will that count against the achievment ??? or will i still get the achievvment for killing all the behomeneths???)

i have like 1 of each type of weapon dlc and vannila all im missing is a few uniques ... what should i too many to select from :/ ran out of minigun ammo last night cant belive i actually used 5000+ rounds!!! ah well i still got like 650 shotgun shells and the pitt is still added on so i could make like 6.5k more ???

i hate my energy weapons skill every energy weapon i use makes globs of ash or goo 100% of the time :/ are there any energy weapons that do not make goo puddles or ash piles or if tehy do its liek 1/1000 kills ??? (besides melee my melee skill is like epic low i think its still 15 i havent found teh bobble head and im level 30)

This should help: http://www.youtube.com/watch?v=o-SvO44MS2w&fmt=18

And for the achievement it doesn't matter how the Behemoth dies, as long as it dies. I play with tons of mods, so i prefer mini-nuke IEDs with my stealth characters (mine+mini-nuke+Behemoth = :nuke:), Fat Man with my tank, and plasma weapons with my EW character