Battlefields were locations used during wars for battles. During their travels, the Doctor and their companions came across several battlefields.
The First Doctor and the Twelfth Doctor returned Archibald Hamish Lethbridge-Stewart to the World War I battlefield he was supposed to die in Ypres, 1914. (TV: Twice Upon a Time)
In his fourth incarnation, the Doctor landed in the battlefield of a war fought between Sontarans and Sycons. (AUDIO: The Eternal Battle)