Sintra, Portugal (Day Trip from Lisbon)

Sintra is technically 40 minutes from Lisbon by train and often treated as a day trip — which undersells what is one of the most fantastical concentrations of 19th-century Romantic architecture in the world. The hillside above the historic center is dotted with palaces: the candy-striped Pena Palace (a deliberate pastiche of every European architectural style simultaneously), the Moorish Castle, the Quinta da Regaleira (with its initiatic wells and Masonic symbolism), and the Monserrate Palace. UNESCO designated Sintra Cultural Landscape in 1995. The strategic advice: arrive on a weekday before 9am, or stay overnight to experience the palaces after the day-trip crowds from Lisbon have departed. Overnight accommodation in Sintra runs from budget hostels to 5-star quinta estates. The microclimate (Sintra sits in a mountain range that captures Atlantic humidity) means the vegetation is genuinely lush in a way that the Lisbon plateau is not.