New techniques for safeguarding valuables in a recreational, public setting are provided. In some aspects of the invention, a specialized portable safe is configured for insertion and securing into sand or other loose ground particles, with at least one removal-resisting edge or anchor. The edge or anchor may be shaped to facilitate insertion into the ground, but resists removal until switched for release by an authorized user. In further aspects, the invention comprises a tamper-detecting alarm. In other aspects, a compartment access door permits the placement and removal of valuables from a compartment of the safe, even when the safe is installed in the ground. In still other aspects of the invention, new wireless locking, unlocking and alerting techniques are provided. In some embodiments, computer hardware and tracking tags and beacons are provided, and trigger locking, unlocking and location alerts to aid a user in locating the safe.