Hello traveler! That's a great trip you're planning to three beautiful cities in South Korea.

Best Time to Visit:
The best time to visit Seoul, Incheon, and Suwon is from March to May (spring) or from September to November (autumn). These periods provide the most comfortable weather and beautiful seasonal scenery.

Route and Accessibility:
Fly into Incheon International Airport which serves both Seoul and Incheon. From the airport, you can take a train or bus to Seoul. High-speed trains called KTX are also available throughout the country, making Suwon easily accessible from either city.

Accommodation and Booking:
All three cities have a wide range of accommodation options, from luxury hotels to budget-friendly guesthouses. Booking in advance is recommended, especially during peak seasons.

Clothing and Essentials:
Pack according to the seasons. During spring and autumn, light jackets and sweaters will suffice. Summers can get quite hot, so light clothes are advisable. Winters are cold, so pack thick clothing, scarves, gloves and thermal wear. Always have an umbrella or raincoat handy as weather can be unpredictable.

Health and Safety:
South Korea is a very safe country to visit, but regular travel precautions should still be taken. Always secure your belongings, stay aware of your surroundings, and keep important local emergency numbers saved in your phone. If hiking or trekking, always let someone know your routes, and keep a first aid kit handy.

Local Etiquette and Respect:
Koreans value respect and politeness. Familiarize yourself with some basic Korean etiquette such as bowing when greeting people. In restaurants, it's considered polite to wait until the eldest person starts eating before you begin.