In the morning, visit the iconic Gateway of India, a historical landmark built to commemorate the visit of King George V and Queen Mary to Mumbai. Take a ferry from here to Elephanta Caves, a UNESCO World Heritage site featuring beautiful rock-cut caves. Grab lunch at any of the street food stalls around the Gateway. In the evening, head to Colaba Causeway, a popular shopping district where you can find everything from traditional Indian clothes to funky jewelry and antiques.
Start your day at Chhatrapati Shivaji Maharaj Vastu Sangrahalaya, formerly known as the Prince of Wales Museum, to learn about India's art, history, and culture. Have lunch at Trishna, a seafood restaurant that serves some of the best crab dishes in the city. After lunch, visit the Haji Ali Dargah, a mosque and tomb located on an islet in the Arabian Sea connected to the mainland by a narrow causeway. In the evening, head to Marine Drive, a scenic boulevard that offers a beautiful view of the sunset.
If you have time, visit the bustling Crawford Market, where you can buy fresh fruits, vegetables, and spices. Take a day trip to the Kanheri Caves, a complex of Buddhist caves located in the Sanjay Gandhi National Park. To maximize your fun, try taking a local train or bus to get around the city, and don't forget to sample the street food.