Buying adjacent lot?

[nicksavings]

This is something I have never done but I am considering a property in which I can buy the lot next door to bundle it in with the property and make the land much larger which I think could add a lot of value in the long run for a future buyer. I am just not sure if it would be worth it because I don't know if the land is taxed as one property or two if both are owned by the same owner. Does anyone have experience with this?