Python 3 code
###################################################
# Julia valley landscape generation as a whole
# (Matplotlib Contour plot)
###################################################

import matplotlib.pyplot as plt        # import matplotlib modules
from mpl_toolkits.mplot3d import Axes3D
import matplotlib.figure as fg
from matplotlib import cm    # import color maps module
import numpy as np   # import numpy module

fig = plt.figure()  # set 3D figure environment
ax =  fig.add_subplot(111, projection='3d')
ax.view_init(azim=120,elev=60)  # set view orientation
ax.dist = 3.7  # set viewpoint distance
ax.set_facecolor([0.7,0.0,0.0])  # set background color

n = 6    # set number of cycles
dx = -0.1    # set initial x parameter shift
dy = 0.0    # set initial y parameter shift
L = 2.0   # set square area side
M = 200  # set side number of pixels

def f(Z):     # def scale damping of the elevation function
    return np.e**(-np.abs(Z))

x = np.linspace(-L+dx,L+dx,M)     # x variable array
y = np.linspace(-L+dy,L+dy,M)     # y variable array
X,Y = np.meshgrid(x,y)     # square area grid
cX = -0.7454294   # C parameter real part value
cY = 0  # C parameter imaginary part value
C = cX + 1j*cY     # complex C matrix
W = np.zeros((M,M))     # zero matrix of depth values
Z = X + 1j*Y   # complex plane area

for k in range(1,n+1):    # recursion cycle
   ZZ = Z**2 + C
   Z = ZZ
   W =  f(Z)

ax.set_xlim(dx-L,dx+L)    # set x axis limits
ax.set_zlim(dy-L,dy+L)    # set y axis limits
ax.set_zlim(-1.5*L,1.5*L)    # set z axis limits
ax.axis("off")   # do not plot axes
ax.contourf3D(X, Y, -W, 2*n, cmap="jet")   # make contour plot
plt.show() # show plot