Vallda Sandö, Nature reserve in Halland County, Sweden

Vallda Sandö is a nature reserve on Sweden's western coast in Halland County, occupying a peninsula with four headlands, five small islands, and diverse landscapes. The site features salt meadows, sandy beaches, and rocky cliffs spread across 349 hectares.

The area shows Bronze Age settlement patterns, with several large burial mounds located on the headlands of Kalven and Sandöknapp. These monuments indicate early human occupation of this coastal region.

The name Sandö refers to the sandy peninsula, and the reserve also takes in the islets Klöven, Stora and Lilla Björskär and Stora and Lilla Keholmen. On 28 August 1969 Gothenburg's city council voted to buy the Vallda Sandö estate in Särö municipality for 1.8 million kronor to use as a bathing and recreation area.

The reserve is equipped with marked trails, benches, and toilet facilities, with good accessibility between the parking area and the northern beach. Visitors will find adequate infrastructure for a comfortable nature visit.

The flat isthmus is home to salt-dependent plants such as sea plantain (marrisp) and glasswort, recorded in Hallands flora. Parts of the isthmus are closed to visitors from 1 April to 15 July to protect the rich birdlife. The reserve also includes the islets Klöven, Stora and Lilla Björskär and Stora and Lilla Keholmen.