The ornamental design for a fireplace, as shown and described.
FIG. 1 is an upper perspective view of the fireplace showing my design.
FIG. 2 is a front elevation view thereof;
FIG. 3 is a side elevation view thereof;
FIG. 4 is an opposite side elevation view thereof;
FIG. 5 is a back elevation view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines are presented to illustrate that no design features are claimed on the top of the fireplace. The broken lines form no part of the claimed design.