While Bangkok is certainly more famed for its skyscrapers, shopping malls, and heavy gridlock, it's not to say that there aren't some decent spots to enjoy the outdoors in. The best outdoor activities in the City of Angels usually involve getting to the beautiful green spaces that are scattered around the city, the largest of which is Bang Krachao, also known as the "lung" of Bangkok, where you can find plenty of fresh air, bicycles to rent, lakeside canoeing, and more. Other top draws for greenery are the Suan Rot Fai Park, where there are kilometers of bicycle track, also a lake to boat in, and plenty of great picnic spots under the trees. Further in the heart of the city, Lumpini Park is the downtown top draw, and besides having a great jogging course, it is also home to the wonderful annual Bangkok Street Show, featuring avant garde artists, along with the weekend "Concert in the Park" series where you can relax to classical music and enjoy the green. In the north of the city, in addition to Suan Rot Fai, enjoy shopping outdoors at the always frantic Chatuchak Market, and if this gets a bit too hectic for you, continue further north, where Bangkok's island in the Chao Phraya, Koh Kret, makes for a great car free day, where you can walk, rent a bicycle, and truly relax.
Other outdoor activities in Bangkok involve cycling to hidden or lesser known destinations away from the urban sprawl, and outfitters like Spice Roads and Grasshopper Adventures can get you to all the top spots on two wheels or on foot. If being on the ground isn't your idea of fun, why not take to the water and enjoy Bangkok this way. Either head over to the little known floating market of Taling Chan, where you can charter a longtail boat to explore with or just eat to your heart's content, or if you are looking for something a bit more upscale, why not set sail on a dinner cruise with Grand Pearl Cruises.
For something really unique, head over to the Flow House, Bangkok's urban surfing mecca, where you can ride the waves and hone your boarding skills without ever leaving town. This is a real adrenaline starter and great way to beat the heat.
While Bangkok may be urban and gritty, you can still enjoy some outdoor pursuits and find your green space with this handy list.