Curved ruined tiles. Has 4 sizes of circular curves (1x1, 2x2, 3x3, 4x4), along with oval curves (1x2, 1x3, 1x4, 2x3, 2x4, 3x4). All curves come in low, half and full, with 2x2 also having every combination of the three. These are construction kit files, so you need to print a base, a wall and a floor.
Grab em' on thingiverse and let us know what you think in the comments.