This fractal is called Castle. When viewed in 3D, it has an outside wall with towers along the edge.

The formula is z = 1 /( 1 / ((z + 2 + c) - 1 / (z - 2 + c))) which is similar to the formula for parallel resistors from electrical engineering. It took Fracton 25 minutes to make the model on my 8 core Mac Pro. The model has 1.5 million vertices and 2.3 million faces. The 3D image and animation were rendered in Cheetah 3D. Here is a link to a web page:

I will also list the PAR file here for the mail list archivists:

castle { ; Exported from Fracton.

 reset=2004 type=formula formulafile=fracton.frm

 formulaname=F_20120730_1032 passes=1 float=y

 center-mag=-0.666966319204264/4.031208046200374e-1\

 0/166666.66875/1/0/0

 params=-1/1/1/1/-2/0/2/0/0/0 maxiter=2000

 inside=16 periodicity=6

 colors=pH6rH5vH3zH0vH2rG3mE2hD2cB2ZA2U81P71K51F41A\

 30510000330760BA1ED1IG1LJ1PN2SQ2WT2_W2b_3fb3ie3mh3\

 ql4tq3wu1zz0ww1tt2pp3mm5jj6gg7cc8``9YYAXVBURBROBOK\

 BLHBJDBGABD6CA3C80CC4CHH8MJ9RLBWNC`PEeSFkWInZHqaHt\

 cGwfGziFwfFtdFqaEnZEkWEhUEeREaODZMDWJDTGDQDCNBCK8C\

 413000443775BB8EFAIIDLMFPQISUKWXNZ`PbdSegUikXloZpr\

 asvcsvcsvcsvcqsaoq`mnZlkXjiWhfUfdTdaRbZP`XO_UMYRKW\

 PJUMHVKGWJGXHFYGFZEF_DEaBEbAEd9Dg9Cj8Bl8Ao89r78u77\

 r67p67n68l68i59g59e59c5A`5BZ6CW7EU8FR8GP9IMAJKBLMC\

 IOFKQHNSKPUNSWQUYSX_VZ`Y`b`cdcfffihiljlolornrulprk\

 mnikkgihffdddabbZa`W_YSYWPWUMVRITPFRNCQK8OI5RK7TN9\

 WPBYRD`TFbWHeYJg_LiaNkcPneRpgTsiVulYxn_zpawn`tk_pi\

 YmfXjdWgaVcZT`WSYURVRQROPOLOKJNHGMDDLAAKADMAGNAIPA\

 LQAOSARUBUWBXYB__CbaCecChfCkhDnjDqlDtnCqlBmjBjiAfg\

 9cf8_d8Xc6SY5NS4IM3EH29B145000311632943D54G75J87MA\

 8QB9TCAWEBZFCbHEfHBjH9nH7 }

frm:F_20120730_1032 {

; Similar to the parallel resistance formula

a=real(p1),b=real(p2),d=imag(p1),f=imag(p2),

z=0,c1=pixel-p3,c2=pixel-p4:

z=1/(1/(a*(z^b)+c1)+1/(d*(z^f)+c2)),

|z|<100

}