Aha!

Greenhouse

A greenhouse is a building with walls
and a roof made of glass or vinyl.
People build greenhouses to create an environment
where plants can grow under a controlled climate.
This idea of growing plants in an artificially controlled
area has existed since ancient Roman times.
The Roman emperor Tiberius ate a cucumber-like
vegetable every day.
Roman gardeners used artificial
methods to have it available at his
table throughout the year.