It's about as long as Baseball base distances.
(MLB Official Baseball Rules specification)
According to MLB Official Baseball Rules, the distance between baseball diamond bases is 30 yards. While second and home base are located upon the corners of the 27.432 sq. m area created by the bases, first and third base are placed within that square, to better allow the umpires to judge whether a ball is fair or foul.
It's about one-and-one-third times as long as a Cricket Pitch.
In other words, 30 yards is 1.363640 times the length of a Cricket Pitch, and the length of a Cricket Pitch is 0.7333310 times that amount.(per Marylebone Cricket Council / International Cricket Council Law #6)
The length of a cricket pitch, from one bowling crease to the other, is 22 yards. The wickets at either end of the pitch stand 0.7874020 yards tall including the bails.
It's about one-and-two-fifths times as long as a Bowling Lane.
In other words, 30 yards is 1.4320 times the length of a Bowling Lane, and the length of a Bowling Lane is 0.698320 times that amount.(USBC specifications; tenpin; including pin deck)
According to the United States Bowling Congress specifications, a tenpin bowling lane should measure 20.9490 yards. In a Professional Bowling Association game, the lane must be lubricated by about 25 ml (0.85 fl. oz) of oil.
It's about three-fifths as tall as The Chicago Water Tower.
In other words, 30 yards is 0.5850 times the height of The Chicago Water Tower, and the height of The Chicago Water Tower is 1.710 times that amount.(Chicago, Illinois)
The Chicago Water Tower is 51.30 yards tall. The tower's architecture was one source of inspiration behind the design of White Castle fast-food restaurants beginning with "Building Number 8," a prefabricated structure built in Minneapolis, Minnesota in 1936.
It's about three-fifths as tall as The Arc de Triomphe.
In other words, 30 yards is 0.560 times the height of The Arc de Triomphe, and the height of The Arc de Triomphe is 1.80 times that amount.(Paris, France)
The Arc de Triomphe stands 54 yards tall. France's Tomb of the Unknown Soldier from the First World War lies beneath the arch and is commemorated by the first eternal flame to have been lit in modern European history.
It's about one-and-four-fifths times as tall as The Hollywood Sign.
In other words, the height of The Hollywood Sign is 0.560 times 30 yards.(a.k.a. Hollywoodland Sign) (Mount Lee, Hollywood Hills, Santa Monica Mountains, California)
Each of the white letters in the Hollywood Sign measures 16 yards tall. Built as an advertisement in 1923, the sign was intended to stand for only eighteen months.
It's about one-and-nine-tenths times as long as a Semitrailer.
In other words, 30 yards is 1.8750 times the length of a Semitrailer, and the length of a Semitrailer is 0.53330 times that amount.(a.k.a. semi-trailer truck, a.k.a. semi, a.k.a. tractor-trailer, a.k.a. truck and trailer, a.k.a. eighteen-wheeler, a.k.a. big rig, a.k.a. Mack truck, a.k.a. transport, a.k.a. lorry, a.k.a. artic; for box truck; United States Federal length limits)
According to the United States Department of Transportation (DOT), the maximum allowable length of a semitrailer pulled by a road tractor truck is 16 yards (unless superseded by state law). These regulations also allow the vehicles to tow up to 36,000 kg in gross weight.