Porto, Portugal, is a vibrant city known for its charming riverside area, colorful buildings, and rich history. It's perfect for families with its kid-friendly attractions like the World of Discoveries interactive museum and beautiful parks. You can enjoy a mix of city life and nature with scenic river cruises and nearby beaches.

Galicia, in the northwest of Spain, is a stunning region known for its lush green landscapes, rugged coastline, and charming historic cities like Santiago de Compostela. It's perfect for families seeking a mix of nature and cultural experiences, with plenty of child-friendly outdoor activities such as beach days, nature walks, and exploring quaint villages. The region's mild August weather makes it a comfortable destination for your 3-year-old to enjoy.

Copenhagen is a fantastic family-friendly city blending charming urban life with beautiful nature spots. You can explore the famous Tivoli Gardens amusement park, stroll along the colorful Nyhavn harbor, and enjoy the peaceful King's Garden perfect for little ones to run around. The city is known for its excellent public transport and bike-friendly streets, making it easy to get around with a toddler.