Seal Rock is one of the most visible Flatirons from Boulder with its distinctive yellow-and-orange north face. High on the south side of Bear Canyon, this rock offers east-face classics, sporty trad/headpoint climbing, and (as of 2013) two sport routes on its radically overhanging south face. There is also one sport route, the three pitch Sea of Joy on the north face, and a scary trad proposition, Archaeopteryx.
Follow the Mesa Trail south from NCAR, passing the two sharp switchbacks that enclose the Bongo Boulder en route to the top of Radio Tower hill. Fifty yards past the turn-off for the Bear Canyon Trail, which heads west into the canyon, notice a small trail cutting up and right (west) into the trees. This unsigned trail is the Harmon Cave Trail, which takes you past the gated-up Harmon Cave and switchbacks up a steep hill to the south en route to the base of Seal Rock. Stay left for the south face routes or go right to reach Archaeopteryx and Sea of Joy on the north face.
Addendum: There are at least 3 ways to get off this crag from the summit. 1) You can downclimb Shortcut, 5.4. 2) You can do a 50m rappel Sea of Joy's anchor bolts (40 feet East of the summit) on the North face. Note, the rope can get stuck on the pull. 3) Supposedly, you can downclimb 40 feet to the West, then go down a ramp to the Southeast, and then rap 135 feet from an eyebolt.