Hello all. Not long had the base set and loving it already. Newb question. If I defeat an enemy or successfully travel to a location is that card removed from the game or placed in the discard pile? Same question for defeated heroes and allies.

All defeated cards leave play by going to their discard pile.

Cards with victory and specifically written effect are the only exception.

Note that traveling to a location and exploring it are two very different things. A location only goes to the discard pile once it has been explored. You can travel to a location during the travel phase, or as card effects allow. A location is explored once it has sufficient progress tokens on it.