Bonus? They're pretty much everywhere.
Try this 15-minute routine from trainer Adam Griffin, creator of bodeefit.com, a fitness site that specializes in stair-based bodyweight workouts. Do the moves in order, and as many reps as you can—with good form, naturally—for 1 minute, taking a 30-second breather in between exercises.
Foot Speed DrillWorks: butt, thighs, calves 1 of 11
Start on the ground level and step left foot onto stair. Immediately step right foot onto step while simultaneously returning left foot to start.
You want to move lightning-fast; think high knees, but on a step. Repeat as quickly as possible.
Broad JumpWorks: arms, butt, thighs, calves 2 of 11
Using your arms to propel you, leap to jump up 2 or 3 stairs, landing with soft knees on both feet. Return to start; repeat.
Decline Push-UpWorks: shoulders, chest 3 of 11
Start with your feet on a step (4 or 5 steps up from the ground). Place your hands on the ground, about shoulder-width apart.
Bend your elbows to lower your chest to the floor, keeping your hips lifted and back flat. Press through palms to rise back up. Repeat.
Need to modify? Lower your knees.
Step-UpWorks: butt, thighs, abs, obliques 4 of 11
Starting from the ground, step your left foot onto the first stair.
Raise your right knee into the air and bring your left elbow to touch your right knee. Return right foot to start, then left foot. Repeat on opposite side.
Shoulder PressWorks: shoulders 5 of 11
Begin with your feet on a stair 3 steps up from the ground, and your hands on the first step. Pike your hips until your arms and torso are almost vertical.
Bend your elbows to lower your head close toward the step, then press back to start. Repeat.
V-UpWorks: abs 6 of 11
Lie face-up on the ground with your arms extended behind your head, legs extended in front of you, and heels on the second step.
Crunch up and touch your fingers to your toes. Return to start and repeat.
Plank JumpWorks: arms, butt, thighs 7 of 11
Start with your feet on the ground and hands shoulder-width apart on a stair 3 or 4 steps from the ground in a plank position.
Jump your feet up to the step just below your hands, then jump your feet back to start. Repeat.
Army CrawlWorks: Shoulders, arms, abs, butt, thighs, calves 8 of 11
Start with your toes on the ground and forearms on a stair 3 or 4 steps up from the ground.
Crawl up the stairs using only your forearms. Stay on your toes, never letting your hips or knees touch stairs, and keep your abs and butt tight.
Jumping LungeWorks: Butt, thighs 9 of 11
Start with both feet on the ground. Lunge your left foot 2 or 3 steps up and sink low.
Explode up, switching feet in air, to land with right foot in a lunge. Repeat, alternating sides.
Sprint It OutWorks: Butt, thighs 10 of 11
Run as fast as you can up the stairs, touching each stair (or every other stair) with one foot.
Walk back down to the start before repeating.