The tiny village of Puerto de Luna, beside the Pecos River 10 miles south of Santa Rosa, was founded in the 1860s. The drive there is pretty, winding through arroyos surrounded by eroded sandstone mesas on Hwy 91. Once you arrive you'll find an old county courthouse, a village church and a bunch of weathered adobe buildings. It's all quite charming, so long as you're not in a hurry to do something else.
Note to road-trippers planning to continue south: the trip to Puerto de Luna from Santa Rosa is an out-and-back trip. Unmarked dirt roads lead over the mesas from the village to Hwy 84, but they are not a recommended shortcut to the south.