Interlaken is a borough in Monmouth County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 820, reflecting a decline of 80 (-8.9%) from the 900 counted in the 2000 Census, which had in turn declined by 10 (-1.1%) from the 910 counted in the 1990 Census.
Interlaken was formed as a borough by an act of the New Jersey Legislature on March 11, 1922, from portions of Ocean Township, based on the results of a referendum held on May 3, 1922.
Interlaken is a dry town where alcohol cannot be sold.
The area that is now Interlaken was purchased in 1667 by Gavin Drummond from the Lenape Native Americans. It was later part of Ocean Township, which had seceded from Shrewsbury Township in 1849 and included at the time present-day Eatontown, Neptune Township, Neptune City, Avon-by-the-Sea, Bradley Beach, Asbury Park, Allenhurst, Deal, Long Branch, West Long Branch, Loch Arbour, Monmouth Beach, Sea Bright and Oceanport, along with Interlaken itself.
Dr. Francis Weld, a Boston physician, bought a 364-acre (1.47 km2) tract and named it Interlaken Farm, after Interlaken, a peninsula in Switzerland situated between two lakes, that they had just visited, which was similar to the borough's location between two sections of Deal Lake. Weld established the Interlaken Land Company in 1890 to turn his farm into a residential community with avenues named after English lakes and cross streets named after the islands in the Hebrides in the Irish Sea. While the initial effort did not succeed, the Stormfelz-Lovely-Neville Company was hired in 1905 to continue the building project, and the community began its growth.
Interlaken was formed as a borough on March 11, 1922, based on the results of a referendum held on May 3, 1922. The first Mayor and Council of Interlaken were seated on June 26, 1922.
Interlaken remains entirely residential, as was originally intended by its developers.
According to the United States Census Bureau, the borough had a total area of 0.39 square miles (1.01 km2), including 0.33 square miles (0.86 km2) of land and 0.06 square miles (0.15 km2) of water (14.62%).
The borough borders the Monmouth County community of Allenhurst, Asbury Park, Loch Arbour and Ocean Township.
Deal Lake covers 158 acres (64 ha) and is overseen by the Deal Lake Commission, which was established in 1974. Seven municipalities border the lake, accounting for 27 miles (43 km) of shoreline, also including Allenhurst, Asbury Park, Deal, Loch Arbour, Neptune Township and Ocean Township.
The 2010 United States Census counted 820 people, 361 households, and 237 families in the borough. The population density was 2,482.3 inhabitants per square mile (958.4/km2). There were 393 housing units at an average density of 1,189.7 per square mile (459.3/km2).