To fully enjoy Athens and Santorini, 5 to 7 days is usually ideal, offering a good balance between exploring historical landmarks and relaxing amidst stunning island scenery. 

• 2 to 3 days in Athens: This allows enough time to visit major historical sites like the Acropolis, Parthenon, and Ancient Agora, stroll through neighborhoods like Plaka and Monastiraki, and enjoy local cuisine. You can also explore museums and soak in the vibrant city atmosphere. 

• 3 to 4 days in Santorini: This provides time to explore charming towns like Oia and Fira, enjoy the iconic sunsets, visit beaches such as Kamari or Red Beach, and take a caldera cruise. You can also explore the archaeological site of Akrotiri and unwind in the island’s serene environment. 

If you're including Mykonos or other nearby destinations, 7 to 10 days would be more suitable. However, for just Athens and Santorini, a 5 to 7-day trip ensures a well-paced and memorable experience. 

Choosing between Athens and Santorini depends on what kind of experience you're looking for. Athens is perfect for history and culture lovers, offering iconic ancient landmarks like the Acropolis and Parthenon, along with lively neighborhoods and fascinating museums. It’s ideal if you're interested in exploring rich historical sites and enjoying a bustling city atmosphere. In contrast, Santorini is a stunning island known for its breathtaking landscapes, whitewashed buildings, and world-famous sunsets. It’s perfect for those seeking relaxation, romance, and natural beauty. Both destinations offer unique experiences, with Athens offering history and vibrancy, and Santorini offering scenic tranquility and island charm.

Absolutely! The most popular trip duration for travelers visiting both Athens and Santorini, especially when including Mykonos, is between 7 to 10 days. However, if you’re only visiting Athens and Santorini, a relaxed and enjoyable trip can be completed in 5 to 7 days.