  The Daya Bay and RENO experiments have recently observed a non-zero
$\theta_{13}$ at more than $5\sigma$ CL. This has important consequences for
future neutrino oscillation experiments. We analyze these within the LAGUNA
design study which considers seven possible locations for a European neutrino
observatory for proton decay, neutrino, and astroparticle physics. The
megaton-scale detector would be an ideal target for a CERN-based neutrino beam
with baselines ranging from 130 km to 2300 km. We perform a detailed study to
assess the physics reach of the three detector options - a 440 kton water
\v{C}erenkov, a 100 kton liquid argon and a 50 kton liquid scintillator
detector - at each of the possible locations, taking into account the recent
measurement of $\theta_{13}$. We study the impact of the beam properties and
detector performances on the sensitivity to CP-violation and the mass
hierarchy. We find that a liquid argon or water \v{C}erenkov detector can make
a $3\sigma$ discovery of CP violation for $60%-70%$ of the parameter space for
any of the baselines under consideration, although the results for the liquid
argon detector placed at 130 km are slightly worse and only $40%-50%$ is
achieved in this case. The performance of the liquid scintillator detector is
affected by its level of neutral-current background at all baselines. A
$3\sigma$ determination of the mass hierarchy is possible for all values of
$\delta$, for the values of $\theta_{13}$ favoured at $3\sigma$ by Daya Bay and
RENO, for almost all setups with $L\gtrsim 650$ km.
