The measurement of the last undetermined neutrino mixing angle \theta ₁₃ is the main goal of the next generation of neutrino oscillation experiments. The present limit is dominated by the result of the Chooz experiment, which gives sin²2 \theta ₁₃ \lesssim 0.10--0.15 (depending on the true value of \Delta m₁₃²), at 90 \% confidence level. Double Chooz is a next generation reactor experiment aiming at exploring \sim 80 \% of the currently allowed parameter region, with a new detector at the Chooz site. The aimed sensitivity requires both the statistical and systematical errors to be significantly reduced with respect to past reactor experiments. In particular, the success of the project depends on the reduction of the systematics, made possible by the installation of a near identical detector and by the improvement of the detector design. The experimental concept and the status of Double Chooz are reviewed. Some of the accomplishments of the project R\&D will be shortly discussed.

PACS numbers: 14.60.Pq