Silver Travertine Tumbled Paving Patio Cobble Tiles

Ground moves. Clay shrinks in summer and swells in winter, tree roots lift, and a sub-base settles unevenly over its first few years. A large paving slab spans that movement rigidly and eventually cracks or rocks. A small cobble does not span it at all: each unit sits more or less independently, so the surface follows a gentle change in level rather than fighting it, and any single piece that does move can be lifted and re-bedded without disturbing its neighbours. The same independence lets cobbles turn a curve, wrap a circular bed or run along a meandering path, none of which a rectangular slab does without cutting.

Tumbling supplies the rest of the character. Every edge is eased and every face broken, so a newly laid path looks settled rather than installed, which is generally the point of choosing cobbles at all.

Travertine is porous and its open pores hold water. Bed on a properly drained base, use an external sealer, and re-treat as the surface weathers.