mantelpiece; mantel
Refers to the shelf above a fireplace. A straightforward noun with no special usage notes.
I displayed a photo on the mantelpiece.
Compound of 炉 (ro, 'hearth, fireplace') and 棚 (tana, 'shelf'). The reading ろだな is a straightforward combination of the on'yomi of 炉 and the kun'yomi of 棚.