Mountainside Borough, New Jersey, is for nature lovers.  In 1895, Mountainside was separated from Westfield Township and became its own community.

Most communities have ball parks, swimming pools and scheduled activities.  Mountainside abounds in recreation facilities. Echo Lake Park (139-acre park with two lakes, ball fields and playgrounds) has boating, fishing, picnicking and skating,  as well as scheduled activities such as the Summer Music Festival (Wednesdays, from June through August).  Watchung Reservation (2,000 acre wooded reservation) boasts fishing, hiking, horseback riding, model airplane flying, and cross country skiing.   It features an arboretum, athletic field, bridle trails, a cross country ski course,  nature trails, picnic areas, playground, and the deserted village of Feltville.  The Watchung Riding Stable boasts extensive programs for young and old.  The Trailside Nature & Science Center & Planetarium offer programs and special events.  During the winter season,  the municipal tennis courts are opened for ice skating.

The "Jigsaw Line between Mountainside and Westfield"  grants the historic Miller-Cory House, circa-1740, a living museum to be operated by The Westfield Historical Society. Famed today as a museum and educational facility for the study of East Jersey farm life in the 18th and early 19th century.  The Miller-Cory House is a historical jewel in the Westfield, Mountainside and Union County crown.