10-Day Adventure Itinerary in Portugal

• Day 1: Lisbon - Upon arrival in Lisbon, explore the historic district of Alfama, known for its vibrant colors and narrow streets. Visit the São Jorge Castle, a Moorish citadel that offers stunning views of Lisbon. End the day by listening to some traditional Fado music while enjoying a glass of wine.
• Day 2: Sintra - Just a short train ride from Lisbon, Sintra is a fairytale town filled with forested hills, opulent palaces, and extravagant gardens. Visit the National Palace of Pena, a colorful Romantic-era palace, and the mysterious Quinta da Regaleira with its hidden tunnels and grottoes.
• Day 3-4: Algarve - Head south to the Algarve, the southernmost region of Portugal, known for its stunning beaches, clear waters and limestone cliffs. Spend two days hiking along the Seven Hanging Valleys Trail, exploring the caves, and surfing or swimming in the ocean.
• Day 5-6: Coimbra - Coimbra is home to one of the oldest universities in Europe, and the city has a vibrant student life. Take a walking tour of this medieval city, visit the Biblioteca Joanina, one of the most beautiful libraries in the world, and try the local delicacy "Leitão" roasted piglet at a traditional restaurant.
• Day 7-8: Douro Valley - Visit the Douro Valley, a UNESCO World Heritage site, famous for its terraced vineyards and wine production. Take a river cruise, visit the Quinta do Vallado winery for a wine tasting, and enjoy the breathtaking views over the valley.
• Day 9: Guimarães - Guimarães is often called the "birthplace of Portugal" because it is where the country was founded in the 12th century. Visit the Guimarães Castle, and the Palace of the Dukes of Bragança, a majestic building that houses a museum of decorative arts.
• Day 10: Porto - Finish the trip in Portugal's second largest city, Porto. Take a walking tour through the colorful streets of the Ribeira district, cross the Ponte de Dom Luís I bridge to Gaia, and marvel at the stunning view of the city from the Miradouro da Vitória.

Time and Costs Estimates

• Lisbon - São Jorge Castle (2 hours, $10)
• Sintra - Palace of Pena (3 hours, $15)
• Algarve - Seven Hanging Valleys Trail (2 days, $0)
• Coimbra - Biblioteca Joanina (1 hour, $5)
• Douro Valley - Quinta do Vallado winery (3 hours, $30)
• Guimarães - Guimarães Castle (2 hours, $10)
• Porto - Ribeira district walking tour (2 hours, $0)
• Total Estimated Costs: $70

Transportation

Public transportation is quite good in Portugal, with trains and buses connecting most cities and towns. For some of the more remote areas like the Algarve or Douro Valley, it may be worth renting a car to have more flexibility. The estimated total cost for transportation in Portugal is around $150, and travel time will vary depending on the destinations and mode of transportation.

Useful Tips

If you have more than 10 days, consider adding a few days in Madeira, an island paradise filled with mountains and lush vegetation. If you have less than 10 days, consider skipping the Algarve or Douro Valley, as they are more remote and require more travel time. Also, be aware that the summer months can be quite crowded and hot, so consider traveling in the shoulder months of May-June or September-October for better weather and fewer tourists.