Absolutely, Figueres, Girona, and Cadaqués are lovely places to visit in northeastern Catalonia in Spain. Here are some travel tips:

Best Time to Visit:
The best time to visit these Spanish towns is during the spring (April to June), when the weather is warm and pleasant. Autumn (September to November) is another good time to travel with mild temperatures.

Route and Accessibility:
From Barcelona, the quickest way to Figueres is by AVE high-speed train, which takes slightly more than half an hour. From Figueres, Girona is an hour away by regional train. Cadaqués is about an hour and a half's drive from Girona. Consider renting a car for flexibility.

Altitude and Acclimatization:
Spain is not known for high altitudes in the areas you're traveling to. All three cities are at sea level or close to it, so you don't need to worry about acclimatization.

Accommodation and Booking:
You'll find various accommodation options in all three towns from budget hostels, middle-range hotels to luxurious villas. Booking in advance is recommended, particularly if you're visiting during the peak season.

Clothing and Essentials:
Summer can get quite hot, so light clothing is suggested. Pack a good pair of comfortable walking shoes, as you'll likely do a lot of walking. Don't forget your swimsuit for the beautiful beaches of Cadaqués.

Health and Safety:
Standard travel advice applies: take out appropriate travel insurance, keep your belongings safe, and stay aware of your surroundings. Tap water is potable in Spain.

Local Etiquette and Respect:
Spanish culture is quite relaxed. However, show respect by following local customs, especially in religious sites. Spaniards often dine late in the evening and enjoy their siestas (rest period) in the afternoon, so plan your activities with these cultural customs in mind. Enjoy your trip!