Activities on Khao San Road are not particularly high class. Many backpackers just chill out in a cafe and watch reruns of Friends while sipping a cold Chang beer. People-watching is also a major activity; this can be done in many roadside bars and pubs along Khao San Road. When all this becomes too stressful, there are plenty of massage parlours around.
May Kaidee's 2 Cooking School
A vegetarian and vegan cooking school in the Sam Sen area north of Khao San Road. You'll shop at the local market to pick fresh ingredients and learn meat-free traditional Thai recipes as well as unique food such as the delicious pumpkin hummous. The owner has been an experienced vegan cook for many years and has a recipe book available for purchase. Those interested need to give at least a day or so advance notice if lucky, you can just try to show up at the morning session and they might let you in. The school also has a restaurant with many vegetarian dishes and as a guest house attached to it.
Sor. Vorapin Gym Muay Thai School
If you dare, you might want to learn muay thai Thai boxing. Beginners and walk-ins are welcome. Shorts and gloves are provided at the course. The English instruction may not be too detailed, but key phrases like "punch", "kick", and "one-two" are in place. Wear protection though! If this all gets a bit too heavy for you, it's also possible to sit outside and watch the trainings take place. Saves you 1,000 baht on an actual muay thai match!