When I create a multiplayer game and other users connect to my game, they are unable to see the mineshafts, houses, chests, etc. that I have constructed on the map while I was previously in single player mode before they joined. I have an iphone5 and an ipad mini and users that connect to both devices don't see any of my construction. They are able to connect to my multiplayer game okay, but inside the map, to them the map looks like a fresh new map with no mining or construction on it.

From what I have read on this site and others, the players in multiplayer are supposed to be able to see the construction of the players, right? Thanks.