Dimna Lake is Jamshedpur's premier artificial reservoir and scenic picnic destination at V66V+FWJ, Dimna Road, Dimna/Saldah (Mango area), Jharkhand 832105—built by Tata Steel in 1944 (Dimna Dam on Kharkai River) spanning ~5.5 km²/1,861 acres at Dalma Hills' foothills near Dalma Wildlife Sanctuary (~13-15 km/30-45 min drive from city center, ~2 hours from Dhanbad). Rated 4.5/5 from 340 Google reviews, it's famed for mesmerizing sunrise/sunset views over calm waters/mountains amid lush deciduous forests/migratory birds, fresh air, boating/rowing/jet skiing/kayaking (Tata Steel Adventure Foundation nearby for parasailing/zip-lining/trekking/camping/rock climbing), picnic tables/playground/public restrooms, and serene escapes (~30 min stays)—magical in fog-shrouded Nov-Feb, Jamshedpur's drinking water source. Open daily until ~6 PM (best dawn/dusk); free/low-cost boating (~₹100-300); essential nature complement to urban parks (Jubilee/Sir Dorabji) or adventures (Tata Zoo/Nicco), with scenic drive through rolling greenery—must-visit for photography/picnics amid industrial Jamshedpur.