There are four Grand Slams:
Wimbledon
The French Open is the only one of the four Grand Slam tournaments to be played on clay courts.
Wimbledon is played on grass courts.
Grass courts.
Grass.
Grass.
Wimbledon.
Grass and Clay
Grass/Turf
the Davis Cup and Wightman Cup tournaments
Asphalt gravel clay grass wood synthetic grass carpet
The most prestigious professional Grass Court Tennis Tournament is Wimbledon.