That would depend on your goals.
If you want to play games with your neighbour, you could probably get away with two APs sitting in your windows. Heck, you might be lucky and a power line Ethernet could work.
If you’re a business and want both properties to be one network, with the speed and reliability that you would expect, then you would want a point-to-point system with directional antennas.
And if you wanted minimal interference, you would probably want to look at 60Ghz. E.g: https://mikrotik.com/product/wireless_wire