Tell me your travel style (relaxed, active, foodie, culture, nature), number of travelers, budget range, mobility limits, and any dietary restrictions so I can make specific meal and activity recommendations and check opening hours.
If you don't have a destination in mind, pick one of these suggestions and I will build a ready-to-go 4-day plan: Lisbon (coastal city + historic neighborhoods), Kyoto (temples, gardens, tea houses), New York City (museums, neighborhoods, food), or Reykjavik/Iceland South Coast (waterfalls, glaciers, landscapes).