The Gemara says that King Hezekiah (Chizkiyahu) closed one of the springs of water in (under?) Jerusalem, so the Assyrian army wouldn't be able to use it. Do we have any guesses what exactly that ...
Is visiting Israel a Mitzvah? (visiting as opposed to living) Just some points I would hope an answer to cover: Was it a mitzvah back then? Is it still a mitzvah nowadays? Does the mitzvah apply ...