Lisbon

Here's an ideal itinerary for 3 days in Lisbon, with a focus on museums and other sites:

Day 1:

• Morning: Start your day with a visit to the National Museum of Ancient Art, which houses an impressive collection of Portuguese art from the 12th to the 19th century.
• Afternoon: Head to the Belem district and visit the Belem Tower, a UNESCO World Heritage Site that dates back to the 16th century. Then, visit the nearby Jeronimos Monastery, another UNESCO World Heritage Site that is home to the tomb of Vasco da Gama.
• Evening: End your day with a stroll through the charming streets of the Alfama district, where you can enjoy traditional Portuguese cuisine and live Fado music.

Day 2:

• Morning: Start your day with a visit to the Calouste Gulbenkian Museum, which houses an impressive collection of art from around the world, including works by Rembrandt, Monet, and Renoir.
• Afternoon: Head to the Chiado district and visit the National Museum of Contemporary Art, which showcases modern and contemporary Portuguese art.
• Evening: End your day with a visit to the Bairro Alto district, where you can enjoy a lively nightlife scene with plenty of bars and restaurants.

Day 3:

• Morning: Start your day with a visit to the Lisbon Oceanarium, one of the largest aquariums in Europe.
• Afternoon: Head to the Castle of Sao Jorge, a medieval castle that offers stunning views of the city.
• Evening: End your day with a visit to the LX Factory, a trendy arts and culture hub that is home to a variety of shops, restaurants, and galleries.

Of course, this itinerary is just a starting point - there are plenty of other museums, sites, and neighborhoods to explore in Lisbon depending on your interests. But I hope this gives you a good idea of what you can see and do in 3 days!