  Identifying a zero-range exchange of vector mesons as the driving force for
the s-wave scattering of pseudo-scalar mesons off the baryon ground states, a
rich spectrum of molecules is formed. We argue that chiral symmetry and
large-$N_c$ considerations determine that part of the interaction which
generates the spectrum. We suggest the existence of strongly bound
crypto-exotic baryons, which contain a charm-anti-charm pair. Such states are
narrow since they can decay only via OZI-violating processes. A narrow nucleon
resonance is found at mass 3.52 GeV. It is a coupled-channel bound state of the
$(\eta_c N), (\bar D \Sigma_c)$ system, which decays dominantly into the
$(\eta' N)$ channel. Furthermore two isospin singlet hyperon states at mass
3.23 GeV and 3.58 GeV are observed as a consequence of coupled-channel
interactions of the $(\bar D_s \Lambda_c), (\bar D \Xi_c)$ and $(\eta_c
\Lambda),(\bar D \Xi_c')$ states. Most striking is the small width of about 1
MeV of the lower state. The upper state may be significantly broader due to a
strong coupling to the $(\eta' \Lambda)$ state. The spectrum of crypto-exotic
charm-zero states is completed with an isospin triplet state at 3.93 GeV and an
isospin doublet state at 3.80 GeV. The dominant decay modes involve again the
$\eta'$ meson.
