Advanced Vipassana meditation retreat is planned to be held monthly at Kanjanaburi, in western Thailand.
You must have already done a retreat at Khao Tham.
The most important thing is your strong will to practice.
Please contact Tookata for more information.
Kanchanaburi city is about 3 hours drive from Bangkok. Information about Kanchanburi, the surrounding areas, how to get there, and more, at WikiVoyage