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.
take a ride to your nearest beach on a less desirable day - the foggier, the moodier, the overcastier the better. enjoy exploring the eerie atmosphere, get lost in your solitude and consider the stark contrast of the beach on a sunny day. if i were you, i would avoid swimming, drowning and falling off cliffs. no one will find you.
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: 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.
book yourself an adventure to distant lands exclusively by yourself. the further, the better. take lots of photos, meet lots of people, and break lots of your own personal rules. i'd like to suggest the beautiful city of amsterdam as the location of your solo adventure. it's clean, friendly and full of activities. if you aren't very resourceful, are a little bit shy, or unwilling to try something new, then you'll probably have a really, really bad time. don't die!
every week map out a different way to get to work, school, or that other thing you do regularly during the day and night. if you take the bus, take a different route, or get off a few stops earlier/later to explore the areas around you. if you walk, keep walking cause that's pretty cool, but take different paths to get there. if you drive, take a bike. if you take a bike, walk. if you take a taxi, stop doing that.
if you're lucky enough to have access to your roof, take a moment to go up there at midnight and observe the environment around you. for an extra special treat, wait to do this during a full moon and bring some music with you. two things to note: if you fall, not my fault and if someone thinks you're a robber, jump.
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.