A courtyard is an open area surrounded by the walls of a building or complex. It is outdoor space, but it feels enclosed and private. Courtyards have been used for thousands of years, from Roman domus to Chinese siheyuan to Spanish colonial missions. They provide light, air, and a sheltered place to gather.

In dense urban settings, a courtyard can be a quiet refuge from the street. It can also be a microclimate: walls block wind, and paving and plants moderate temperature. In hot dry climates, a courtyard with a fountain or pool can cool the air.

Courtyards come in many forms. A central courtyard organizes a building around a single open space. A side courtyard attaches to one edge. A series of small courtyards can break up a large building into smaller, more intimate zones.

Design matters. A courtyard with no shade, no seating, and no reason to enter is just a hole in the building. The best ones are designed for specific uses: dining, play, contemplation, or circulation.