Humayun's Tomb in Delhi is a magnificent 16th-century Mughal mausoleum commissioned by Empress Hamida Banu Begum for her husband, Emperor Humayun, and completed in 1570. Recognized as the first garden-tomb on the Indian subcontinent and a UNESCO World Heritage Site, it features elegant red sandstone architecture with intricate white marble inlays, a double dome, and charbagh gardens, serving as a pioneering masterpiece that profoundly influenced later Mughal monuments including the Taj Mahal.