Há uma série irlandesa-australiana de 2004 sobre um portal e personagens como você descreveu. É chamado Câmbio .
Sinopse de Wikipédia :
Foreign Exchange had two major sets, one in Galway, Ireland, and the other in Perth, Western Australia. Brett Miller and his family live underneath their restaurant, only to find a rock that opens a portal into the basement level of O'Keefe's College, an Irish boarding school (which is in reality Castlehackett House, near Tuam, Co. Galway). There he unexpectedly bumps into Hannah O'Flaherty, a student from Galway, who is delighted to learn that when she turns a similar rock on her side of the portal, she can escape the grey and winter of Ireland to the sun and summer of Australia. The show revolves around these two characters, who are the only two to know and use the portal with the exception of Cormac MacNamara, who learns about the portal near the end of the season.