Absolutely! Visiting Ouro Preto, Tiradentes, and São João Del Rei - all UNESCO protected 'Historical cities' in Brazil is indeed a step back in time. Here are some travel tips specifically for these places:

Best Time to Visit:
The best time to visit these cities is between April and September when the weather is not too hot. However, if you want to experience their famous festivals, plan your trip in July for the Winter Festival in Ouro Preto and in August-September for the food festival in Tiradentes.

Route and Accessibility:
All three cities are in the state of Minas Gerais. The nearest major city is Belo Horizonte, reachable by flight from most Brazilian cities. From Belo Horizonte to Ouro Preto you can take a bus or rent a car, the travel time is about 1.5 hours. For visiting Tiradentes and São João Del Rei, you can hire a taxi or bus from Ouro Preto.

Altitude and Acclimatization:
These cities are on the Brazilian highlands but not at a very high altitude, so acclimatization is not really a concern for most travelers.

Accommodation and Booking:
All three cities have a range of accommodations according to your budget. It's always wise to make a booking in advance especially during festival seasons.

Clothing and Essentials:
Carry comfortable footwear as these cities have cobblestone streets. Also, an umbrella or a light rain jacket can come in handy during sudden rains. Evenings can be chilly, so be prepared with a light jacket or a sweatshirt.

Health and Safety:
Brazil does have some health issues concerning mosquitoes, it's suggested to take necessary precautions. Also, do keep in mind that these are old, hilly towns with cobblestones, so be extra careful while walking/ driving.

Local Etiquette and Respect:
These cities have a rich history reflecting their native and African roots. Show respect to the local culture and traditions by acknowledging their values. When visiting churches, dress modestly. Also, it's advisable to understand a bit of Portuguese as English is not widely spoken.