Los Alamos is a town that exists because of a secret. In 1943 the US government chose this remote mesa, once the site of a boys' ranch school, for the Manhattan Project, and J. Robert Oppenheimer's team built the first atomic bombs in the pine forest at the end of a single winding road. The laboratory is still the biggest employer, which gives the town an odd, educated, slightly fenced-in feel. Street names, museums and a surprising number of PhDs in the grocery queue all hint at it.
The setting is dramatic for a different reason. The town spreads across fingers of the Pajarito Plateau, flat-topped mesas of hardened volcanic ash that spill off the Jemez Mountains and end in sheer canyon edges above the Rio Grande. At roughly seven thousand feet the air is thin, dry and bright, and afternoon thunderstorms in July and August can build fast enough to make you reconsider the plan. The road up from the river through the canyon is a good one, climbing in long bends from the valley floor with the whole Rio Grande rift laid out behind you.
For riders, this is a place to arrive and look around rather than to race through. The roads out the back are the real prize: Highway 4 heads west over the rim of the Valles Caldera, a huge collapsed volcano whose grassy floor holds elk herds and mist at dawn, then drops through red rock country toward Jemez Springs and its hot baths. Heading the other way, the same highway passes Bandelier National Monument, where Ancestral Pueblo people cut homes into soft tuff cliffs and left petroglyphs that are still easy to find.
It is also a practical stop. The town has plenty of fuel, a proper main street and ordinary places to eat, and White Rock, a little way down the hill, has more of the same with a canyon overlook. Be aware that the weather up here can run ten degrees cooler than Santa Fe, and in winter the roads carry snow and sometimes ice in the shade. Have a jacket in the bag even when the valley is warm.