Traveling by train combines the chauffeured luxury of a limousine, the awesome power of a battleship, and the rhythmic clickety-clack of a marathon runner in tap shoes. Ride the rails to scenic satisfaction with today's Groupon, which gets you tickets for the Secret City Scenic Excursion Train, operated by the Southern Appalachia Railway Museum. Tours depart from the Heritage Center, located roughly 10 miles west of downtown Oak Ridge. Choose between the following options:

• For $15, you get two adult tickets (a $30 value).
• For $10, you get two children's tickets (a $20 value).

Families who wish to ride the train together can purchase and redeem Groupons for one set of children's tickets and one set of adult tickets at the same time. Children younger than 3 ride free.

The Southern Appalachia Railway Museum's Secret City Scenic Excursion Train transports passengers to the dawn of the atomic age as it winds through 14 miles of eastern Tennessee. Track travelers congregate at the Heritage Center, a former Department of Energy facility, before boarding 1940s-era air-conditioned coaches and kicking off the cruise by chugging through the facility that formerly housed the Manhattan Project.

Powered by 1950s Alco diesel locomotives, trains arc over the placid waters of Poplar Creek and travel through green valleys while tour guides saturate brains with historical info. Coaches clip along Highway 327, curl around Watts Bar Lake, and come full circle to Wheat Station. Each trip is seasonally oriented, with such themes as Spring Colors, Welcome to Summer, Summer Daze, and Fall Colors. During the winter, Santa trains allow passengers to meet St. Nick and measure their beards against his. Though not included in today's Groupon, passengers can purchase souvenirs and snacks from open-air concession cars.

Reservations are required, so check the schedule to set aside seats. Sandals and open-toe shoes are not allowed on the train, and passengers with disabilities requiring assistance must be accompanied by a ticketed caregiver. Trains may not be equipped for all special needs, so check in advance if necessary.