Seion Chapel was opened in 1878, the designer was Richard Owen of Wall, Liverpool and is fairly typical of nonconformist chapels of that period.
St Michael's is some 40m from the foreshore and some 30m east of Aberystwyth Castle.
The first Church was opened in 1787, and was situated to the west of the Assembly Rooms. It is described as a small building that had taken 20 years to build.
The existing large and prosperous late-Victorian building is of 1889-90 by R Nicolson of Hereford. It is constructed of Yorkshire stone with Bromsgrove dressings and Westmorland green slates, in English Decorated style. The west end and tower were completed to an altered design in 1905-1906 by Nicolson and Hartree. The elaborately carved sedilia, piscina, font and Last Supper reredos are by Boulton and Sons of Cheltenham. The carved oak lectern is by Clarke of Hereford to Nicholson's design. Of the stained glass, the east window and north aisle east window are both of 1889, by AO Hemming, in the strong colours of Clayton and Bell. The four later south aisle windows are of 1903, also by Hemming. The north aisle window of 1914 is by Powell.
A few of the early 19th century monuments have been removed to the west porch. The west memorial in the north aisle is by Chantrey.