How a sample map figure could be inserted under the graph in Tikz like below:
The below code plots the 3d coordination.
\documentclass{article}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}
\begin{document}
\begin{center}
\begin{tikzpicture}
\begin{axis}[x={(20,0)},y={(0,20),z={(0,20)}},z={({-20/sqrt(6)},{-20/sqrt(8)})},
grid = both,minor tick num=1,xmin=0,xmax=14,ymin=0,ymax=.01,zmin=0,zmax=17,
ticks=none,clip=false,tick style={opacity=0}]
\draw[-latex, >=latex, thick] (0,0,0) -- (0,0,18) node[left]{};
\draw[-latex, >=latex, thick] (0,0,0) -- (15,0,0) node[below]{};
\draw[-latex, >=latex, thick] (0,0,0) -- (0,8,0) node[left]{};
\end{axis}
\end{tikzpicture}
\end{center}
\end{document}
