I cant find the entrance,i read a bit on Wiki,but still isnt clear to me,Is the entrance on the Hill with the High radiation Level,or is it somewhere else?

any other information to enter this HELL is welcome

The High Radiation level is the main entrance but its pretty much automatic death if you try... the right way is through Little Lamplight caverns just south as it has two entry points after you gain access from the resident kids... Child at Heart perk helps

http://fallout.wikia.com/wiki/Vault_87

http://fallout.wikia.com/wiki/Little_Lamplight

Hope this helps...

oke thanks,i try by Little Lamplight,ive already been there,also in the aria with the Supermutants,but my map still indicates that i heavent been in Vault 87

maybe the Child at Heart Perk,was thinking about that1 because al the other Perks are not much use

The entrance to Little Lamplight is just behind the ticket shack and further in you'll find a barricade at which you'll have to travel to paradise falls to rescue a few of the missing kids or as mentioned the Child at Heart will get you in... once in there is Murder Pass and a locked door you will need repowered by one kid that gives you access to Vault 87