Love Among the Ruins by Warwick Deeping

Dame Duessa had come to Avalon, having heard certain whisperings of Gilderoy, and of a golden-haired Astarte who kept house there. Dame Duessa was a proud woman and a passionate, headstrong as a reformer, jealous as a parish priest. She boasted a great ancestry and a great name, and desires and convictions in keeping. She was a woman who loved her robe cupboard, her jewel-case, and her bed. Moreover, she pretended some affection for the Lord Flavian her husband, perhaps arrogance of ownership, seeing that Dame Duessa was very determined to keep him in bonded compact with herself. She suspected that the man did not consider her a saint, or worship her as such. Yet, termagant that she was, Dame Duessa could suffer some trampling of empty sentiment, provided Fate did not rob her of her share in the broad demesne and rent-roll of Gambrevault.

Avalon was a castle of ten towers, linked by a strong curtain wall, and built about a large central court and garden. A great moat circled the whole, a moat broad and silvery as a lake, with water-lilies growing thick in the shallows. Beyond the moat, sleek meadows tufted with green rushes swept to the gnarled piers of the old oaks that vanguarded the forest. The black towers slumbered in a mist of green, girded with sheeny water, tented by the azure of a southern sky.