  We reexamine the novel phase diagrams of antiferromagnetism (AFM) and
high-Tc$ superconductivity (HTSC) for a disorder-free CuO$_2$ plane based on an
evaluation of local hole density ($p$) by site-selective Cu-NMR studies on
multilayered copper oxides. Multilayered systems provide us with the
opportunity to research the characteristics of the disorder-free CuO$_2$ plane.
The site-selective NMR is the best and the only tool used to extract
layer-dependent characteristics. Consequently, we have concluded that the
uniform mixing of AFM and SC is a general property inherent to a single CuO$_2$
plane in an underdoped regime of HTSC. The $T$=0 phase diagram of AFM
constructed here is in quantitative agreement with the theories in a strong
correlation regime which is unchanged even with mobile holes. This {\it Mott
physics} plays a vital role for mediating the Cooper pairs to make $T_c$ of
HTSC very high. By contrast, we address from extensive NMR studies on
electron-doped iron-oxypnictides La1111 compounds that the increase in $T_c$ is
not due to the development of AFM spin fluctuations, but because the structural
parameters, such as the bond angle $\alpha$ of the FeAs$_4$ tetrahedron and the
a-axis length, approach each optimum value. Based on these results, we propose
that a stronger correlation in HTSC than in FeAs-based superconductors may make
$T_c$ higher significantly.
