Tennis polo
The sport is played on a grass field between 80 and 100 yards long and 50 to 65 yards wide. The goal area is a semicircular line with an 11-yard radius and the penalty mark at 13 yards from the goal. An experimental rule has a second semicircular line on the field with a 17-yard radius. Generally, a field for gridiron football or soccer can be used.
Baseball
Unlike those of most sports, baseball playing fields can vary significantly in size and shape. While the dimensions of the infield are specifically regulated, the only constraint on outfield size and shape for professional teams following the rules of MLB and Minor League Baseball is that fields built or remodeled since June 1, 1958, must have a minimum distance of from home plate to the fences in left and right field and to center. Major league teams often skirt even this rule. For example, at Minute Maid Park, which became the home of the Houston Astros in 2000, the Crawford Boxes in left field are only from home plate. There are no rules at all that address the height of fences or other structures at the edge of the outfield. The most famously idiosyncratic outfield boundary is the left-field wall at Boston's Fenway Park, in use since 1912: the Green Monster is from home plate down the line and tall.