I used to help organise the European Talbot Workshop, an annual workshop focusing on a specific topic in topology, homotopy theory, or geometry.
The goal is to bring together a range of graduate students (masters, PhD, and some post-docs included) together with two mentors and experts in their respective areas, and to discuss a particular topic in depth for a week, somewhere in the European countryside.
The topics change every year and have included structured ring spectra, TQFT's, duality in stable homotopy and algebra, free loop spaces, algebraic K-theory, and operadic calculus.