Absolutely, it sounds like a great trip! Here are some travel tips to make your journey to the southwestern region of Saudi Arabia more enjoyable:

Best Time to Visit:
Although these places can be visited year-round, the best time to visit Abha, Tanumah, and Najran would be during the cooler months, from November to March.

Route and Accessibility:
Abha, Tanumah and Najran can be accessed through King Khalid airport in Abha and Najran Domestic Airport in Najran. Renting a car for your stay is a convenient option to move between these cities.

Altitude and Acclimatization:
Considering Abha's high altitude (over 2,200 meters above sea level), it might take a while for you to acclimatize. Take it easy on the first day to prevent altitude sickness.

Accommodation and Booking:
There are many hotels and vacation homes in Abha, Tanumah, and Najran, ranging from budget to luxury. Many hotels can be booked online in advance, which is advisable during peak tourist season.

Clothing and Essentials:
Saudi Arabia is a conservative country. Men and women are recommended to wear loose and modest clothing covering most of their body. Do not forget to pack sunblock, sunglasses, and a hat to protect yourself from the strong sun.

Health and Safety:
Avoid drinking tap water and opt for bottled water instead, especially if you're not accustomed to the local water. Carry prescriptions for any medication you're bringing along, as certain drugs are banned in Saudi Arabia.

Local Etiquette and Respect:
Saudi Arabian culture is warm and hospitable. A firm handshake is the typical greeting. Handing over items or eating with your left hand is considered impolite. Show respect for the local customs and traditions, especially during the holy month of Ramadan.