Aghavallen church appears to date from the fifteenth century, and its conversion from Catholic to Protestant use reflects a pattern common across Ireland in the post-Reformation centuries. By the time it was finally closed in 1858, replaced by a newer church built nearby, it had already become the preferred burial ground for several of the area's prominent families.

The Crosbies of Rusheen House, along with the Ponsonby, Colt, Pope, and Sandes families, all have tombs here, making Aghavallen an unusually concentrated record of local gentry burial practice. A survey carried out by Laurence Dunne in 2010 recorded fifteen tombs within the church and graveyard, with a possibility that a further few remain hidden within the inaccessible west end of the ruins. The variety of tomb types is notable: strong-box, house-shaped, coffin-shaped, lean-to, and simple box-shaped forms all appear. Alongside twelve named tombs, 131 named headstones were recorded, as well as sixty-six unnamed graves, many marked only with unhewn stone or simple iron and wooden crosses. Five rectangular nineteenth-century grave slabs were also found, of which all but one could still be read.

The eastern limits of the site are heavily overgrown, with mature sycamore trees and dense undergrowth making that section damp, dark, and difficult to move through. The boundary walls are built from uncoursed rubble sandstone and limestone set in mortar and capped with upright stones known as soldiers. Entry is through a wrought-iron gate between two tall round rubble-stone piers, with a stepped stone stile set into the wall beside it for those who prefer not to use the gate. The ivy-covered north wall becomes harder to examine the further east it runs, and the overall impression is of a place that has been slowly reclaimed at its margins, even as its centre remains legible.