Off the top of my head, it seems a good invasion landing site (amphibious) needs the following:
[li]Firm sand (not muddy or saggy, so as to not bog down the invading vehicles);[/li][li]A lack of major obstacles and big rocks;[/li][li]Nearby roads or paths that provide direct access to nearby objectives such as a town or broader network;[/li][li]A lack of hiding/sniping places for nearby defenders;[/li][li]Close proximity to invader nation, so as to enable direct supply/reinforcement routes by invader;[/li][li]A place where there isn’t much difference between high tide and low tide; (or is it *good *to have a big difference between tides?)[/li][li]A far distance from nearby enemy bases (“enemy” = the invaded country);[/li][/ul]
But at the same time, all of these elements are undesirable, too, in the sense that the enemy would also know perfectly well that they make for a good landing beachhead and hence would pay more attention to guarding such locations.
What other factors come into play?