Hello! It's exciting to hear about your upcoming trip to Portugal. Here are some travel tips for your visit to Lisbon, Porto, Sintra, and Coimbra.

Best Time to Visit:
The best time to visit Portugal is during spring (March to June) and autumn (September to October) when the weather is not too hot, but still pleasant, and the tourist crowds are smaller than in the peak summer season.

Route and Accessibility:
Lisbon and Porto have international airports, so these are likely your primary points of entry. From Lisbon and Porto, you can reach Sintra and Coimbra respectively via train or car. The train services are reliable and efficient in Portugal, providing fast and convenient transportation.

Accommodation and Booking:
All the cities you plan to visit have a wide range of accommodations from luxurious hotels to budget-friendly hostels. It's recommended to book your accommodations well in advance, particularly if you're traveling during peak season.

Clothing and Essentials:
Pack clothing according to the season of your visit. A good pair of walking shoes is essential as you'll likely be exploring the cities on foot. Don't forget to bring a sunscreen and a hat for protection against the sun.

Health and Safety:
Portugal is generally safe for travelers. Still, keep an eye on your belongings, in particular in crowded areas or public transportation. If you have specific health concerns, ensure you have an appropriate travel insurance covering health care and emergency evacuation.

Local Etiquette and Respect:
Portuguese people appreciate politeness. A few words in Portuguese, like 'por favor' (please) or 'obrigado'/'obrigada' (thank you, for male/female speakers respectively) can go a long way. When visiting religious sites, dress respectfully and avoid loud conversations.