“Fernweh” is a German word for “farsickness,” the opposite of homesickness.
It comes from fern (meaning “far”) and weh (defined as “pain,” “misery” or “woe”). Fernweh, then, is “farsickness” or a “longing for far-off places,” especially those you’ve not yet visited.
The remedy for fernweh may not be quite so simple as it is for homesickness. Then again, you may not want to squelch it.