Any of the excursions suggested here can be done as a leisurely day trip from Tucson , leaving after breakfast and returning in late afternoon. A major part of any of these day trips is the drive itself, and it’s best to avoid the interstate and take the scenic two-lane backroads.
If you want to spend a few days exploring southeastern Arizona, hiking along the San Pedro River or in the Huachuca Mountains, I’d suggest staying in Bisbee , where you’ll find some of the best historic hotels and bed-and-breakfasts in the state, and making excursions from there.
A trip to the Chiricahua Mountains  from Tucson is definitely an all-day trip, and you really need to spend at least two days to truly enjoy this wonderful place. It’s a long, empty drive to the Chiricahua National Monument , but at the end of it is one of the most spectacular sights this side of the Grand Canyon.
Let’s say you only have one full day for excursions. In that case, head to Kartchner Caverns  (1 hour from downtown Tucson) and Bisbee, taking the scenic route. It’s a good idea to call ahead and reserve tickets to the caverns, though it’s not as important to do so these days at it once was. Leave after breakfast, have lunch in Bisbee before heading to the caverns, and you’ll be back in the Old Pueblo by dinner time, unless you fall in hopeless love with the off-kilter hillside town.
If you’re headed down to Nogales, Arizona  and across the border, I’d recommend doing so around lunch or dinner time, as eating at one of the restaurants in the tourist district in Nogales, Mexico , is one of the joys to be had across the line. If you’re across the line after dark, be careful. It’s easy to get caught up in the scene—downing margaritas with lunch, then tequila shots, then some guy you don’t know comes up from behind and in broken English offers to take you to a strip club…Remember that you’ve got an hour or so worth of driving north on I-19 to make it back to Tucson .