Sure, these cities in Iran are steeped in culture and history. Here are some travel tips for your visit to Kashan, Isfahan, Yazd, and Shiraz.

Best Time to Visit:
Spring (March-May) and Autumn (September-November) are the best times to visit, when the weather is comfortably warm during the day and cooler at night.

Route and Accessibility:
Tehran's Imam Khomeini International Airport is the main international gateway to Iran, and there are regular flights connecting to Kashan, Isfahan, Yazd, and Shiraz. Additionally, these cities are well connected by road, so intercity buses or private cars are a good mode of transport.

Altitude and Acclimatization:
These cities are not at high altitudes, so acclimatization should not be an issue. However, take care to stay hydrated, especially if you are travelling during the warmer months.

Accommodation and Booking:
Iran offers a range of accommodations, from budget guest houses (mehmansaras), traditional houses now converted into boutique hotels, and luxury hotels. It's recommended to book your accommodations in advance.

Clothing and Essentials:
Due to the prevailing customs and legal requirements in Iran, women are required to wear loose fitting clothing and a headscarf in public places. Men should wear long trousers. Comfortable shoes are imperative as you will likely be doing a lot of walking. Sunscreen, sunglasses, and a hat are also useful items to carry.

Health and Safety:
Iran is generally considered safe for travelers. However, normal precautions apply. Carry travel insurance, basic medicines, and keep hydration in check, especially during the warmer months.

Local Etiquette and Respect:
Iranians are warm and hospitable. A basic understanding of Farsi is appreciated, but not necessary. Respect local customs and traditions. Remember to remove shoes when entering mosques or traditional houses.