There are few naturally occurring topological or geographical features to suggest the parallel development of such a border.
Two other implausible borders that show up all the time are the current Russian-Finnish border (in OTL dating from the settlement after the Winter War in 1940) and the Algeria-French West Africa border (arbitrarily drawn at the end of the 19th century). Less noticeable is the Swiss-Italian border, which only became the way it is now during the French Revolutionary Wars. And this doesn't even begin to take into account pretty much every single modern-day border in Africa, all of which were only created by European colonial powers in the 19th and 20th centuries.
Perfectly straight borders (whether it be north-south, west-east, or any other variation) also seem to have an annoying habit to pop up from time to time, even in completely nonsensical locations - although this is more often due to laziness on the part of the map-maker in question rather than simple ignorance.
In the AH.com The Series episode MONTANA HOWERY AND THE MANTLE OF N00B, a planet featured in which the Chinese and Russian empires built a gigantic border wall across Kazakhstan, large enough to contain hotels and restaurants inside it, and had their priests curse it so it would never be violated. This is, therefore, the Damned Kazakh Border.