Built in 1870, the Cimarron Redoubt is an improvised fortification in Ashland, Kansas. It was built to provide some protection to the major trade route in the Cimarron River.

The southwestern portion of Kansas was once one of the areas largely affected by the Comanche War (1867-1875), the traffic that goes through the Fort Dodge trail needs to be protected. To do this, US Army soldiers made a quick move to build some fortifications. One was located north of Ashland, the other was placed south, which is what is known today as the Cimarron Redoubt. It was later used to protect the area from hostile Indians, but when that was settled; the fortifications were left to the civilians.

The Cimarron Redoubt is made more historical by being useful later on. It served various purposes for the locals, including functioning as a post office at one time.