Start your journey at the iconic Gateway of India, a historic monument overlooking the Arabian Sea. You can take a boat ride to the nearby Elephanta Caves and explore the ancient rock-cut temples. Then head to Chhatrapati Shivaji Terminus, a UNESCO World Heritage Site, and admire the stunning architecture of the Victorian Gothic style train station.
Start your day early by taking a walk along the Marine Drive, a charming promenade that hugs the coastline. Then take a cab to Haji Ali Dargah, a mosque and tomb located on an islet in the Arabian Sea. Spend some time admiring the Indo-Islamic architecture, and enjoy a delicious meal at one of the many street food stalls nearby. End the day by catching a movie at Liberty Cinema, one of the oldest cinemas in Mumbai.
Start your day by shopping at Colaba Causeway, a vibrant street market famous for its trendy clothes, jewelry and handicrafts. Then head to Crawford Market, one of Mumbai's oldest and most famous markets, which sells a variety of goods including fruits, vegetables, spices, and household items. End your day with a visit to Jehangir Art Gallery, which showcases contemporary Indian art.
Take a break from the hustle and bustle of the city and explore the Sanjay Gandhi National Park, a nature reserve located on the outskirts of Mumbai. Take a guided tour of the Kanheri Caves, a series of rock-cut Buddhist monasteries and temples that date back to the 1st century BCE. End your day with a relaxing picnic at Tulsi Lake, which offers stunning views of the surrounding hills and forests.
If you have more time, consider taking a day trip to the nearby hill station of Lonavala or the beach town of Alibaug. If you have less time, skip one of the destinations from Day 2 or Day 3. Remember to carry a refillable water bottle and sunscreen, and wear comfortable shoes as there is a lot of walking involved.