Morlais Quarry as Crimean Battlefield
The Doctor finds herself trapped in the Crimean War due to a misbehaving TARDIS but learns that the Russian's have been replaced by the Sontarans.
Source: Cultbox
“Chapter Two: War of the Sontarans” Filming Locations
Separated in time, the Doctor and her companions must deal with the strange appearance of the Sontaran army on Earth at various points in time.
Doctor Who episode “Chapter Two: War of the Sontarans” was filmed in Cardiff in the United Kingdom.
51 Llanmaes Street as Dan Lewis's House
Dan appears back on his street but flees when he is targeted by a group of Sontarans for breaking curfew.
Alley (north of The Parade, west of East Grove) as Alley near Dan's House
Dan runs from the Sontarans down an alley but is saved by his parents weilding frying pans.
Alley (north of Newport, east of West Grove) as Liverpool Street
Dan and his parents take cover in their car from a passing Sontaran patrol.
Cardiff Container Port as Liverpool Docks
Dan's parents show him to the docks where the Sontarans are building their ships and he sneaks in alone.