HYDRA Research Base
The HYDRA Research Base was a laboratory set up by HYDRA in a 19th Century Fort outside Novi Grad in Sokovia.
The fort was used by HYDRA for Super-Soldier experiments under the command of Wolfgang von Strucker. These experiments were eventually successful after HYDRA was able to obtain Loki's Sceptre, and the laboratory created the first successful Super-Soldiers created since the Second World War, Wanda and Pietro Maximoff.
The fortress was damaged in the attack on the HYDRA Research Station by the Avengers, and further damaged by Ultron. Although the main structure of the fort is still standing, it is now considered structurally unsafe and the Sokovian government has errected fences around the buildings to prevent visitors.
Defenses
The facility was heavily fortified, with machine gun turrets, watch towers, and energy shields in addition to the historic fortress. It was also surrounded by dense forrest, making approach by large forces difficult.
History
Prior to its use by HYDRA, the fort had been abandonned since the fall the Soviet Union. Before that it had been used as a military base by the Soviet government, and before that the Austro-Hungarian army.