St Martin's church dates from 1585 and was consecrated in 1603. The building is in Scaldian Gothic style (alternating brick and limestone) and the church has been restored in various stages, beginning in 1980 and ending in 2000.
The building is made up of a prominent front section and nave flanked by very narrow side aisles and gabled chapels. It ends in a chancel with pentagonal chevet adjoining two sacristies as well as other low structures (mid-20th century). The front section is divided into five levels by dripstone cordons. The first level features an arched doorway with the keystone stating the year of construction (1585). The second level has a relief of St Martin topped by a pediment bearing the coat of arms for the town of Ath. The third level is reduced by its chained pitch. Atop the building is a square octagonal spire.
The nave, which is edged by false side aisles, is lit by two windows (18th century) and has a stuccoed false vaulted ceiling. It is made up of three bays separated by Gothic arches. The side chapels and the chancel, which has five walls, have Gothic arch windows without tracery, alternating stone and brick.
The 16th-century sacristy (south-east) is lit by windows with straight lintels on toothed uprights. Note in the south-west corner the presence of a Gothic stone niche brought from the former refuge at Cambron abbey in Ath. On the inside, the floor is in bluestone, with the exception of the floor of the chancel and the first bay, which is covered in black and white marble and decorated by a star. To the right of the church is the cross, also listed since 1941 and created in 1754.