Where to Invest to get a good value later ? (Bangkok)

Hi everyone,
Swadee kha..

Being an expat out here in Bangkok, I would like to seek advises on where to invest money legally to get double the capital after a certain period of time. The banks offer very low rate of interest on Savings or any other account for expats.

I plan to set up my own business after Protected content , so would like to fix some amount right now to get a good value later.

Good suggestions are always welcome and will be much appreciated.

Dimple