The Kopineshwar Mandir is a Hindu temple dedicated to Shiva, considered one of the oldest and most significant religious sites in the Konkan region. The current structure is an 18th-century rebuild of a much older temple, with a characteristic black stone architecture and a tank in which the image of the deity is reflected. The temple is active — priests conduct daily pujas, and the precincts fill with worshippers on auspicious days and festivals.
The temple sits near the waterfront of the old town, close to Masunda Lake, in a part of Thane that still has some of its older character. It is open to all visitors outside puja times; a modest dress code is expected (shoulders and knees covered). The surrounding streets of the old town have some small tea stalls and snack vendors that are worth exploring.