Abstract: Sandals are disclosed herein. A sandal includes a sole assembly and a retention structure. The sole assembly is configured to transition between a flattened conformation and a raised conformation. The sole assembly has a forefoot region, a heel region, and a midfoot region. The sole assembly includes a foot bed configured to face the wearer's foot and an outsole extending underneath the foot bed and configured to contact a ground surface. In the flattened conformation, the sole assembly is at least substantially flat. In the raised conformation, the sole assembly is contoured to raise the heel region relative to the forefoot region. The sole assembly is biased toward the raised conformation, and includes a conformation bias element configured to bias the sole assembly toward the raised conformation.