This looks like an excellent summer school:
http://www.itp.uni-hannover.de/saalburg/
It will be taking place 31 August – 11 September 2015 in Wolfersdorf, Thueringen, and organized by Arthur Hebecker, Ivo Sachs, Stefan Theisen, Andreas Wipf, and Olaf Lechtenfeld.
Topics and lecturers:
A.N. Schellekens: Conformal field theory
R. Wald: Black hole thermodynamics
J. Zinn-Justin: Renormalization group: an introduction
S. Hollands: Quantum fields in curved spacetime
J.W. van Holten: Dynamical space-time and gravitational waves
Registration is open.
Cost: Travel plus 150 Euro. Deadline is 30 June.