St Mark’s Church Dundela is a prominent landmark dominating Sydenham Hill in East Belfast, built to designs by the prolific High Victorian Gothic architect William Butterfield. The church is the only example of his work in Northern Ireland. Alastair Coey Architects carried out a detailed condition survey of the exterior in 1991 which identified widespread stone decay with an estimated cost of £1.3m. The work was completed between 1995 and 1999 in three stages. Further phases of work include a new heating installation, re-modelling of the choir and new glazed porches to a value of £250,000 in 2007, and the structural stabilisation of the internal stone tracery over the baptistery to a value of £100,000.