Flights to MaramuresCluj Napoca, Bucharest and Budapest
Cluj Napoca airport is the nearest and has good Wizzair flights from Luton to Cluj Napoca.
Baia Mare has an airport that is closer and has flights from Austria if you are coming in from international connections but you will hard pushed to beat the London Wizz Air flights in terms of cost and availability. A lot of international flights come into Budapest, where you can get the train or bus to Baia Mare. There are also good Bucharest flight connections you can get and then come up to Breb on the overnight train from Bucharest to Sighetu Marmației