Dipoles And Monopoles:

You may at first think that the magnetic field around a current-carrying wire is caused by a monopole or that there are not any poles at all since the concentric circles apparently do not originate or terminate anywhere. Though, think of any geometric plane having the wire. A magnetic dipole, or pair of opposite magnetic poles, is created by the lines of flux going halfway around on either side. There in effect is two such "magnets" stuck altogether. The south poles and the north poles are therefore not points but instead face of the plane backed right up against each other.

The lines of flux in the vicinity of a magnetic dipole forever connect the two poles. Few flux lines are straight in a local sense, though in a larger logic they are always curves. The greatest magnetic field strength about a bar magnet is near the poles, where the flux lines converge. About a current-carrying wire, the maximum field strength is close to the wire.