An amphitheatre or amphitheater is an open-air venue used for entertainment, performances, and sports. The term means "on both sides" or "around" or "place for viewing".[from wikipedia]

An automatic fountain the sprays water vertically when a bus passes over that spot on the second floor,the floor directly under the Roof Garden.

The rooftop garden at the Salesforce Transbay Transit Center contained more than just plants, it alsooffered placed to relax and places to play.

Plants are mainly multicellular, predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, plants were treated as one of two kingdoms including all living things that were not animals, and all algae and fungi were treated as plants. However, all current definitions of Plantae exclude the fungi and some algae, as well as the prokaryotes (the archaea and bacteria).[from wikipedia]

The term, 'sign' comes from the old French signe (noun), signer (verb), meaning a gesture or a motion of the hand. This, in turn, stems from Latin 'signum' indicating an"identifying mark, token, indication, symbol; proof; military standard, ensign; a signal, an omen; sign in the heavens, constellation."[from wikipedia]