Boston, USA, is a vibrant city known for its rich history, beautiful architecture, and delicious seafood. It's a great starting point for your trip with its easy access to international flights and charming neighborhoods. Don't miss the historic Freedom Trail and the bustling Quincy Market for a taste of local culture and cuisine.

Washington, D.C. is a city rich in history and culture, offering iconic landmarks like the National Mall, Smithsonian museums, and the Capitol Building. It's a great starting point for your trip, with excellent flight connections and vibrant neighborhoods to explore before you head to the Basque Country. The city also boasts a diverse culinary scene, perfect for food lovers.

Bilbao is the vibrant heart of the Basque Country, famous for the iconic Guggenheim Museum and its blend of modern architecture with rich history. The city offers scenic riverfront views, a lively food scene with authentic Basque pintxos, and charming old town streets to explore. September is perfect for enjoying pleasant weather while discovering Bilbao's cultural gems and nearby natural landscapes.