if you live near a body of a water, there's a good chance someone can offer you a canoe to rent. find them, rent it and explore said body of water. if you live in san francisco, you've got even more options. if you live in san francisco and feel up to a three hour drive, may i suggest traveling north to the big river estuary in mendocino where the fine lads of catchacanoe will let you get on a boat. don't fall asleep and drift into the ocean though, they don't like that very much.
san francisco: take a trip across the golden gate bridge and follow the road toward mount tam. you'll come across a small parking area before you get to the top that leads into the woods. follow a map down the steep, rocky paths to the bottom where you will be greeted by alpine lake. take note as you head downward that the hike back up will not be as fun.
san francisco: travel through the quaint neighborhood streets of the upper haight and head further up passed buena vista park to roosevelt way and museum way to discover a large rock formation at corona heights. as you ascend the hill, you will be greeted with spectacular views of the city. be sure to snap a photo or two while you're there, but don't drop your camera/iphone.
san francisco: make your way up the sweeping hills of the city to presidio st and pacific st where you'll find an entrance back down into san francisco's presidio. walk down and around, through the trees and about the greens on paved ways and ad hoc paths. there's a ton of secluded bits to explore. when you start running into tourists and too many people, you have my permission to get out of there immediately.
san francisco: ride, bike or bus over to the very expansive golden gate park where you'll find lots of hidden delights and surprises like the rose garden, secretly tucked away beyond the museums. spend time exploring the varietals, enjoying the lovely scents and admiring the colors, shapes and sizes of the seemingly endless beds of roses. always remember one thing: roses have thorns so don't go falling in.
san francisco: grab a group of good pals and head north over the golden gate bridge to the top of mount tam. follow the narrow, curvy roads up and up through the hills and trees. pick one of the many scenic places to stop and hike on up just before sunset. may i suggest a nice bottle of wine to sip as the sun sets. be sure to drink in moderation unless you actually want the hike down to get ugly.
san francisco: make your way through the city and up the hills to 18th and missouri in potrero hill. take a moment to consider the long wooden fence painted in vibrant greens with splashes of bright color and note the multiple "eyes" staring at you from every direction. spend some time grouping the eyes together to form little characters and faces - but don't linger too long, someone may get suspicious, creeped out, or think you're just weird.
san francisco: journey down to pier 45 on the embarcadero for an epic adventure into the creepy museum of antique penny arcade games. be sure to take plenty of quarters with you to witness the century old "games" including the bizarre opium-den, a graphic french execution, and an uncomfortable jolly jack laugh. If you're prone to nightmares and hate fun, i suppose this isn't the place for you.
san francisco: hop in a car and head north over the golden gate bridge to calistoga where hot springs and mud baths are a plenty. book an early morning massage at indian springs and enjoy an entire day of nothingness, lounging by the enormous geyser-fed mineral pool. in the likely event you lose your ability to move your body due to extreme relaxation, i suggest you avoid the deep end.
san francisco: cross the golden gate bridge and drive up up and up into the marin headlands. as you wind along the roads, passing the stunning views, you will come to the former Nike Missile launch site at Fort Barry. take a moment to stare out at the missiles sunning themselves in the scene. do not climb the fence and attempt to "ride" them, no matter how tempting. it's just a bad idea.
san francisco: when you're all alone, head to the building at one market late at night. pass the security guard(s), move beyond the elevators and find the open space in the middle. look up from the center point and take in all the golden lines and shapes. take note of the hum coming from the prism structure. feel the empty space and the height of your surroundings. run if you get in trouble.
san francisco: maneuver your way to the corner of pacific and divisadero st where you find an enormous brick mansion with carousel horses in many of the windows. take a moment and imagine the kind of people who live there, then walk away quickly. very very quickly.
navigate to your nearest ridiculously large hill. in san francisco, may i suggest the pacific heights / russian hill area. once at the bottom, begin to walk up the hill backwards for a different experience and a more spectacular view of your city. in the event a small dog comes running along behind you and you fall down because you're directionally off, don't say i didn't warn you.