Ramayana
प्राकारैर्विविधाकारैः शोभिताश्च शिलातलैः । तत्रैव च वनोद्देशे वैडूर्यमणिसन्निभैः ॥ 7-42-13 ॥
They were beautified by enclosing walls of various forms and by slabs of stone; and there too, in that part of the grove, by stones resembling cat's-eye gems.
english translation