Flens kyrka

The church began as a low-roofed hall church with a nave, probably originally covered by a simple timber ceiling, with its entrance in the south-west corner. A sacristy stood to the north and a modest timber porch to the south, the latter demolished around 1740. During the 1500s the nave was extended and given two vaulted bays.

In the 1640s these vaults were painted by Nils in Tunatorp, a farmer-painter known for basing some of his work on older engravings, giving parts of the decoration a deceptively archaic appearance. The vault paintings draw on New Testament subjects; a second, unidentified painter decorated the western vault with images of Old Testament prophets. The choir was added in the 1600s, funded by the Rosenhane family of Stenhammar Castle, and a new sacristy followed in 1746, paid for by Countess Ebba Charlotta Douglas, also connected to Stenhammar.

The present tower was built at the very end of the 1700s, replacing an older, deteriorating bell tower; once it was finished, the old south-west entrance was walled up. The church's vaults are of a distinctive type known as 'gubbvalv', where the mason shaped the vault ribs into grotesque, face-like figures — a feature shared with a small number of other Södermanland churches, including Bettna and Vrena.

The altarpiece, showing the Descent from the Cross, was completed in 1793; its painter is unrecorded, though the frame was made by a Norrköping manufacturer. Among the church's older furnishings are two stone font basins dated to the 1100s, suggesting an earlier church once stood on the site. A carved cross from a fourteenth-century triumphal crucifix, along with fragments of an older altarpiece depicting the Throne of Grace, survive and are kept near the site of the original entrance.

The church's organ has been rebuilt several times, most recently in 1981, retaining a nineteenth-century case front from an earlier instrument.