I like Gathige's advice

But since you're still very young and with lots of cash to spare, maybe you should go for a long term project like planting trees(silviculture).

Buy a large piece of land in the bundus after finding out which trees do well there(KFS do help) and plant then watch, tend & wait. In 7,10 or 20 yrs, you should be worth much more

That should be better than Nairobi plots

But only for the patient