I'm not a teacher!
With no romantic I would say so:
A beach is a territory along the shoreline usually equipped with sun loungers, tents, towel stations, rescue center, water attractions and other leisure-time entertainments.
With a little bit romantic I would say so:
A beach is a place where earth meets the sea, where you can walk barefoot in the moist sand under the blue sky when the waves come and go away leaving freshness mixed with happiness, where the seagulls cry filling the scene with freedom, eternality and ease...