By law, all land belongs to the government, they will allow us the right to use it in a certain amount of time, they can give us more time later when it's expired. But the most fantastic thing is: they can take it back anytime they want because they are the real owners, not you or me.
So, invest in land in Vietnam is really risky, except you have good relationship with the government and by some miracle way you can keep your land forever.
But we are allowed to fully own our apartments, so apartments are real properties, land is not. When they want to take back the land where your apartment is standing on, they'll have to buy your apartment. Sometime the price is super lower than the market price, that's why sometime people have to strike back the government for getting a better price (striking back the Communist Vietnamese government is totally illegal and you can go to jail by doing so), but it most cases it's acceptable.