What does the Quran use as an analogy for paradise?
The Quran specifically and repeatedly refers to Paradise as a garden, described as being infinite in size and wealth, with fruits and company and every conceivable comfort or desire. Keep in mind that the following passages are translated into English, and surely lose some of their literal meaning in the translation from Arabic:
Surely for the godfearing awaits a place of security, gardens and vineyards and maidens with swelling breasts, like of age, and a cup overflowing.
(The Koran Interpreted 78:31-34)
And view with one another, hastening to forgiveness from your Lord, and to a garden whose breadth is as the Heavens and the Earth, prepared for the godfearing.
(The Koran Interpreted 3:133)
Many archaeologists and those who study architecture suggest that the Quran's references to and descriptions of gardens contributed greatly to how they were designed, in ancient times and even today.