Address of 8.asm-peb, TEB (ntdll! RTLGETCURRENTPEB get Peb)

If you don't want to write the assembly, you can use this.

Ppeb Ntapi Rtlgetcurrentpeb ();
Ppeb Peb=rtlgetcurrentpeb ();

Its assembly is:

ntdll! RTLGETCURRENTPEB:
7c97efa9 64a118000000    mov     eax,dword ptr fs:[00000018h]
7c97efaf 8b4030          mov     Eax,dword ptr [eax+30h]
7C97EFB2 c3              ret

FS:[0X18] point to TEB itself

Come on, Almighty WinDbg:

0:000> DD fs:[0x18] L1
0053:00000018  7efdd000
0:000> r $teb
$teb =7efdd000

0:000> DT _teb-y processenvironmentblock @ $teb 
test1!_teb
   +0x030 processenvironmentblock:0x7efde000 _PEB