The foundation stone for the Old Chapel, or "Mount Zion" as it was originally known, was laid on 17th July 1909. The photograph below is of the opening day in 1910.

In 1932 the Wesleyans and the Primitive Methodists united to become the Methodists, and Mount Zion was the only Methodist church in Calstock. The Methodists sold the building in the early 1990s, and it became know as "Harmony Hall," before being sold on to Peterloo Poets in 1998. The building was by now in a dilapidated condition, and Peterloo, under the helm of Harry and Lyn Chambers, obtained over £200,000 of Lottery / Arts Council funding to restore the building as an office, warehouse and performance space.

In 2009 the building was acquired by Calstock Arts Community Interest Company with the remit to run it as an arts centre for the benefit of the local community.