First revealed at Gamescom 2016, Overwatch’s new map, Eichenwalde is a Hybrid map set in Germany. The payload for the map is a battering ram that the attacking team must escort into the castle.
Taken from the description of the map trailer from the official Overwatch Youtube channel:
“The site of one of the most famous battles during the Omnic Crisis, it was here that the leader of the Crusaders, Balderich von Adler, and a handful of his best soldiers made a last stand against an advancing automaton army. Outnumbered and outgunned, they were ultimately slain during the resulting combat. However, thanks to their valiant efforts, the German military was able to push back the omnic offensive and win the fight .”
The reason for escorting the battering ram to the castle is to reclaim von Adler’s corpse which rests in the throne room. The backstory and surroundings of the map gives a feeling of a Middle Age type siege where the attacking team is trying to breach the castle. Eichenwalde will mostly be close quarters as the tight streets, small rooms, and European style city leaves little room for long-range battles. As a result of this, the map favors the defending team quite a bit as chokepoints become much easier to hold than an open map.