Ideally, you are looking for an area where land shows tremendous growth on investment. Alternatively, you may invest in an area where the investment growth is not necessarily that high, but the rental income will covers all the costs.
The influential reason is by how much you can finance the expenditure, but both have merit and are worth investigating as soon-to-be Landlord.
What are town planners proposing for the medium- to long-term? Is there a planned major road, sports stadium, train route, shopping center, or school that may either detract from or boost your property investment?
Go out with knowledgeable real estate or Land agents in the area and pick their common sense!