Many visitors come to Thailand specifically for meditation retreats. Bangkok has a few centres offering courses, but the city is honestly not the best place for deep practice. If you are serious about meditation, head south to Suan Mokkh near Chaiya for their renowned monthly silent retreats. In Bangkok, Wat Mahathat near Sanam Luang offers daily meditation sessions that work well for a taste of the practice.
Meditation
Meditation retreats and daily sessions at Buddhist temples