The Mongols also built arch dams in modern-day Iran. Their earliest was the Kebar Dam built around 1300, which was high and long, and had a radius of . Their second dam was built around 1350 and is called the Kurit Dam. After was added to the dam in 1850, it became tall and remained the tallest dam in the world until the early 20th century. The Kurit Dam was of masonry design and built in a very narrow canyon. The canyon was so narrow that its crest length is only 44% of its height. The dam is still erect, even though part of its lower downstream face fell off.