Hello! That sounds like an exciting trip you're planning in Northern Ireland. Here are some travel tips for your visit to Derry, Belfast, and Bangor.

Best Time to Visit:
The best time to visit Northern Ireland, including Derry, Belfast, and Bangor, is from May to September when the weather is usually warm and the days are longer. This period encompasses several local festivals and events which also make it a vibrant time to visit.

Route and Accessibility:
There are multiple ways to explore these cities. All three cities are well-linked by bus and train services. Northern Ireland's International Airports located in Belfast make accessibility much smoother. From the airport, you can easily reach Derry, Belfast, and Bangor by renting a car or taking a taxi or bus. Getting around within the cities is quite easy by public transport or on foot.

Accommodation and Booking:
All three cities offer a range of accommodation options suitable for different budgets, from luxury hotels to budget-friendly guesthouses and hostels. It's highly recommended to book your accommodations in advance, particularly if you plan to visit during the peak tourism season.

Clothing and Essentials:
The weather in Northern Ireland can be changeable, so layers are key. Carry waterproof clothing and an umbrella, comfortable shoes for walking, a good quality jacket, and warm clothing for the evenings. Don't forget your travel documents, travel insurance, and any prescription medicines you need.

Health and Safety:
Northern Ireland is generally safe, but it's always a good idea to stay vigilant, especially in crowded areas. Follow common travel safety measures such as keeping your valuables secure and maintaining copies of important documents. If you have any health issues, consult your doctor before travelling and bring any necessary medications.

Local Etiquette and Respect:
The locals in Northern Ireland are known for their friendly and welcoming nature. It's respectful to follow general UK customs and etiquette. Do wait your turn in queues, be respectful of the local culture and history, and avoid discussions around politics, especially related to the region's past conflicts.