Stony Batter is a historic defence installation at the north-eastern end of Waiheke Island, Auckland, New Zealand. It is sited within a 50-acre (200,000 m2) scenic reserve of the same name, owned by the New Zealand Department of Conservation (DOC). The park serves double duty as a historical (Category 1 Historic Place) and nature reserve, containing unusual rock formations, associated with an extinct volcano, three significant bush blocks and three concrete gun emplacements with an extensive tunnel system, reputed to be the largest in New Zealand. 

Stony Batter was part of a counter-bombardment battery system progressively being installed in the Hauraki Gulf from the 1930s. Composed of various gun batteries, such as at Whangaparaoa, Motutapu Island and at Stony Batter, as well as having observation posts such at Rangitoto Island (command post) and Tiritiri Matangi Island, it was supposed to engage enemy naval forces entering the inner gulf. Ranges would have been too far beyond the line of sight of over 30 km, thus the need for a complex set of observation points and communication lines), as well as at least initially beyond the range of most enemy ships' ability to retaliate.

The work on the installations, sans guns, was completed behind schedule in 1944, and had by then ballooned from initial estimates of £140,000 to £327,966, excluding the costs of the guns. By 1945, the immediate threat of war had subsided, so work stopped and the work force moved on to hydroelectric projects elsewhere.

Take a tour of the site, but also remember to visit all the other wonderful places on Waiheke Island as well.