Sure! These are all charming Portuguese villages, each with its own unique atmosphere. Here's what you need to know:

Best Time to Visit:
Generally, the best time to visit Portugal is in the spring (March to June) or during the fall (September to October) when there're fewer tourists, the prices are relatively low, and the weather is mild.

Route and Accessibility:
Lisbon and Porto have the most international flight connections. From both cities, you'll likely need a rental car to reach these rural locations. Monsanto and Sortelha are about 40 minutes apart by car. Marvão is about a two hour drive south from Monsanto, and Óbidos is just over two hours west from Marvão, along the coast.

Altitude and Acclimatization:
All these locations are at low to moderate altitudes, so acclimatization should not be an issue.

Accommodation and Booking:
There are plenty of charming guesthouses in these villages where you can experience local hospitality. Be sure to book your accommodations in advance, particularly if you're visiting during high season (July and August).

Clothing and Essentials:
Pack lightweight clothing for sightseeing, but include layers as mornings and evenings can be cool. Comfortable walking shoes are essential as village streets can be steep and cobblestoned.

Health and Safety:
Standard precautions apply: stay hydrated and don't forget your sunscreen. Be cautious on narrow village streets and while driving on rural roads.

Local Etiquette and Respect:
Respect local customs and traditions. Portuguese people appreciate it when visitors put in the effort to speak even a few words of their language. Remember to say "Por favor" (Please) and "Obrigado" (Thank you).