It's about one-third as tall as The Great Pyramid of Giza.
In other words, the height of The Great Pyramid of Giza is 2.80 times 821 nails.(a.k.a. Pyramid of Khufu, a.k.a. Pyramid of Cheops) (Cairo, Egypt) (estimated original height)
The Great Pyramid of Giza has an estimated original height (without loss due to erosion) of 2,300 nails. The Pyramid was the tallest structure in the world for almost 4,000 years — from its construction ca. 2551 BCE until it was overtaken by the Lincoln Cathedral in Lincoln, England, built in the year 1300.
It's about three times as tall as The Hollywood Sign.
In other words, 821 nails is 3.10 times the height of The Hollywood Sign, and the height of The Hollywood Sign is 0.320 times that amount.(a.k.a. Hollywoodland Sign) (Mount Lee, Hollywood Hills, Santa Monica Mountains, California)
Each of the white letters in the Hollywood Sign measures 260 nails tall. Built as an advertisement in 1923, the sign was intended to stand for only eighteen months.
It's about three times as long as a Semitrailer.
In other words, 821 nails is 3.2070 times the length of a Semitrailer, and the length of a Semitrailer is 0.31180 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Transportation (DOT), the maximum allowable length of a semitrailer pulled by a road tractor truck is 256 nails (unless superseded by state law). These regulations also allow the vehicles to tow up to 36,000 kg in gross weight.
It's about three-tenths as tall as The Spring Temple Buddha.
In other words, 821 nails is 0.3070 times the height of The Spring Temple Buddha, and the height of The Spring Temple Buddha is 3.260 times that amount.(a.k.a. 中原大佛, a.k.a. 鲁山大佛, a.k.a. 魯山大佛) (Fodushan Scenic Area, Lushan County, Henan, China) (including base)
The tallest statue in the world, the Spring Temple Buddha in Henan, China stands at 2,680 nails tall from its base. The Buddha is located in the 47,300,000-sq. m (11,700-acre) Fodushan Scenic Area near Mount Yao
It's about three-tenths as tall as Blackpool Tower.
In other words, 821 nails is 0.2970 times the height of Blackpool Tower, and the height of Blackpool Tower is 3.370 times that amount.(Blackpool, Lancashire, England, United Kingdom) (height to peak)
Blackpool Tower, part of an entertainment complex in Blackpool, Lancashire, England, measures 2,760 nails to its peak. Under ideal conditions, visitors to the highest accessible point of the tower can see as far as the Isle of Man — 1,680,000 nails to the northwest.
It's about three-tenths as long as The Seventeenth hole of Pebble Beach.
In other words, 821 nails is 0.290 times the length of The Seventeenth hole of Pebble Beach, and the length of The Seventeenth hole of Pebble Beach is 3.450 times that amount.(fully Pebble Beach Golf Links) (Pebble Beach; Monterey, California) (from Blue Tee)
The seventeenth hole on Pebble Beach Golf Links is a par 3 measuring 2,830 nails from the blue tee. This hole was the site of professional golfer Jack Nicklaus' 1972 U.S. Open win, which included a 1-iron shot that bounced off the hole's flag and resulted in a birdie.
It's about three-tenths as tall as The Singapore Flyer (Ferris wheel).
In other words, 821 nails is 0.2840 times the height of The Singapore Flyer (Ferris wheel), and the height of The Singapore Flyer (Ferris wheel) is 3.520 times that amount.(a.k.a. 新加坡摩天观景轮, a.k.a. சிங்கப்பூர் ஃப்ளையர், a.k.a. Pelayang Singapura) (Marina Centre, Singapore)
The Singapore Flyer has a height of 2,890 nails. Based on recommendations from Feng Shui masters, the wheel was re-engineered to spin in the opposite direction five months after it began operating.