Anything that's boring, tedious, or so dull that it puts you to sleep can be described as wearisome. Long bus rides and long classroom lectures can both be wearisome.
The adjective wearisome is good for describing things that seem to last forever, that require repetition, or that are otherwise both boring and mentally exhausting. Always being told "Be careful!" by your parents can be wearisome, and typing data into a computer all day is also wearisome. The original, fifteenth century meaning of wearisome was "weary" or "tired," but it quickly came to mean "making one weary," from the Old English root werig, "tired."