Is it true that according to the Koran, Mosques are to be built on conquered grounds?

...remember, Muslims are encouraged to marry 4 wives and BEAT them if they act disobedient too ! (Qu'ran: 4.34) ...and if "you" refuse to submit to their moon-god (Allah) "they" are instructed to KILL the infidel as well ! (Qu'ran: 2.256)