Oriental historian Basil Gray believes

Iran has o unique art to the world which is excellent in its kind.

Caves in Iran’s Lorestan province exhibit painted imagery of animals and hunting scenes. Some such as those in Fars Province and Sialk are at least 5000 years old.
Painting in Iran is thought to have reached a climax during the Tamerlane era when outstanding masters such as Kamaleddin Behzad gave birth to a new style of painting.
Paintings of the Qajar period, are a combination of European influences and Safavid miniature schools of painting such as those introduced by Reza Abbasi. Masters such as Kamal-ol-molk, further pushed forward the European influence in Iran. It was during the Qajar era when “Coffee House painting” emerged. Subjects of this style were often religious in nature depicting scenes from Shia epics and the like.Says writer Will Durant:

Ancient Iranians with an alphabet of 36 letters, used skins and pen to write, Instead of earthen tablets.

Such was the creativity spent on the art of writing. The significance of the art of calligraphy in works of pottery, metallic vessels, and historic buildings is such that they are deemed lacking without the adorning decorative calligraphy.

Illuminations, and especially the Quran and works such as the Shahnameh, Divan Hafez, Golestan, Bostan et al. are recognized as highly invaluable because of their delicate calligraphy alone. Vast quantities of these are scattered and preserved in museums and private collections worldwide, such as the Hermitage Museum of St. Petersburg and Washington’s Freer Gallery of Art among many others.