Humayun's Tomb and the Taj Mahal have some of the largest Persian gardens in the world, from the era of the Mughal Empire in India.
The Avestan word pairidaēza-, Old Persian *paridaida-,[note 1] or Median *paridaiza- "walled-around", (i.e., a walled garden), were borrowed into Elamite (partetaš) and Akkadian, and later as Ancient Greek: παράδεισος, romanized: parádeisos.
The same word was used to describe the Elamite custom of creating a sacred grove or husa surrounding a royal grave that was the site of worship of the deceased king.
[3] The garden's construction may be formal (with an emphasis on structure) or casual (with a focus on nature), following several simple design rules.
Persian gardens may originate as early as 4000 BC, but it is clear that this tradition began with the Achaemenid dynasty around the 6th century BCE.
[4][dubious – discuss][verification needed] Decorated pottery of that time displays the typical cross plan of the Persian garden.
The design sometimes extends one axis longer than the cross-axis and may feature water channels that run through each of the four gardens and connect to a central pool.
Hallmarks of these formal gardens are a geometric layout following geometric and visual principles, implemented to nature by water channels and basins which divide the enclosed space into clearly defined quarters, a principle that has become known as Chahar Bagh (four gardens), waterworks with channels, basins, fountains and cascades, pavilions, prominent central axes with a vista, and a plantation with a variety of carefully chosen trees, herbs.
[6]The invasion of Persia by the Mongols in the thirteenth century led to a new emphasis on highly ornate structure in the garden.
[clarification needed] The Mongols then carried a Persian garden tradition to other parts of their empire (notably India).
Mughal gardens have four basic requirements, symbolizing four allegorical essentials for the afterlife: shade, fruit, fragrance, and running water.
[8][9][10] The Safavid dynasty (seventeenth to eighteenth century) built and developed grand and epic layouts that went beyond a simple extension to a palace and became an integral aesthetic and functional part of it.
Trees and trellises largely feature as biotic shade; pavilions and walls are also structurally prominent in blocking the sun.
Irrigation may be required, and may be provided via a form of tunnel called a qanat, that transports water from a local aquifer.
Designers often place architectural elements such as vaulted arches between the outer and interior areas to open up the divide between them.
An early description (from the first half of the fourth century BCE) of a Persian garden is found in Xenophon's Oeconomicus in which he has Socrates relate the story of the Spartan general Lysander's visit to the Persian prince Cyrus the Younger, who shows the Greek his "paradise at Sardis".
In this story Lysander is "astonished at the beauty of the trees within, all planted at equal intervals, the long straight rows of waving branches, the perfect regularity, the rectangular symmetry of the whole, and the many sweet scents which hung about them as they paced the park"[12] The oldest representational descriptions and illustrations of Persian gardens come from travelers who reached Iran from the west.
Unlike the park it is a private area often affixed to houses and often consisting of lawns, trees, and ground plants.