Set just north of the Arkansas River, this was once the natural and official border between the US and Old Mexico (until 1846), and was once a cultural crossroads. The old adobe fort, with its timber-beamed ceilings, has been beautifully restored. It's staffed by knowledgeable guides in period clothing (dressed like old trappers and with an Old West twang).
You'll see an old blacksmith's shop and a wood shop, and the general store is stocked with rifles, ammunition, sacks of grain, barrels of sugar, cases of wine, whiskey and buffalo pelts, and furnished with 19th-century antiques. You can snoop through the rooms and climb onto the fort walls where you can peer down onto and over the cottonwood-shaded Arkansas River to the south. Out front are old covered wagons and wagon-wheel canons.