A three day workshop on various ways of testing gravity — cosmological, astrophysical and terrestrial. This is a topical theme, in part because of the growing interest in modified gravity theories motivated by the unexplained nature of dark matter and dark energy, and in part by improving technologies that open opportunities for new types of tests. The workshop will bring together experimentalists, observers and theorists, with a mixture of invited and contributed talks, and plenty of time for discussions. A one day school on cosmology and gravity for students will directly precede the main workshop.